use cce_ui::widget::Handle;
 use cce_ui::engine::{Application, LogicalPosition, LogicalSize, WindowSettings};
 use cce_ui::widget::{
     Button, WidgetHost, ElementState, MouseButton, Key, NamedKey, KeyEvent, TextBox,
     MouseScrollDelta
 };
 use futures::StreamExt;
 use std::sync::{Arc, Mutex};
 use std::io::Write;
 use tokio::sync::oneshot;
 use std::ops::Deref;
 
 const ACCENT: [f32; 4] = [0.30, 0.50, 0.32, 1.0];
 const TOGGLE_OFF: [f32; 4] = [0.16, 0.16, 0.24, 1.0];
 /// `TOGGLE_OFF` for a control that is not a control — see `fingerprint_interactive`.
 const TOGGLE_INERT: [f32; 4] = [0.11, 0.11, 0.15, 1.0];
 
 
 #[derive(Clone, Debug)]
 enum AuthResult {
     Success,
     ExitWindow,
     Failure(String),
     FingerprintStatus(String),
 }
 
 #[derive(Clone, Debug)]
 enum AppMessage {
     PasswordVerify,
     FingerprintScanStart,
     AuthDone(AuthResult),
     Cancel,
     PromptReceived(String, bool), // (prompt, echo)
     StatusReceived(String, bool), // (message, is_error)
 }
 
 struct GuiRequest {
     username: String,
     message: String,
     cookie: String,
     tx_result: oneshot::Sender<Result<(), String>>,
 }
 
 static ACTIVE_REQUEST: Mutex<Option<GuiRequest>> = Mutex::new(None);
 static ACTIVE_SENDER: Mutex<Option<calloop::channel::Sender<AppMessage>>> = Mutex::new(None);
 
 /// Cancellation state for every cookie polkitd has handed us, not just the one
 /// whose window is up. Requests queue (the GUI runs on the main thread, one at a
 /// time), so a CancelAuthentication can arrive for a cookie whose window has not
 /// opened yet — or has not finished starting. A single active-cookie slot dropped
 /// both of those on the floor and stranded the dialog.
 struct CookieState {
     active: Option<String>,
     cancelled: Vec<String>,
 }
 
 static COOKIES: Mutex<CookieState> = Mutex::new(CookieState {
     active: None,
     cancelled: Vec::new(),
 });
 
 /// Whether the simulated authenticator may stand in for PAM.
 ///
 /// Simulation reports success on its own, and in polkit mode that success is handed to
 /// polkitd as `Ok(())` — granting the privileged action with nothing checked. So a live
 /// request vetoes it outright, whatever asked for it: `CCE_AUTH_SIMULATE` once won here,
 /// which turned every pkexec in the desktop into a silent auto-yes.
 ///
 /// Gate on the dangerous state, never on an allowlist of the ways in. Kept as a pure
 /// function of its inputs so the veto is settled by the test suite rather than by
 /// arranging a live authentication bypass to check it.
 fn simulate_allowed(polkit_mode: bool, env_requested: bool, uid: u32) -> bool {
     !polkit_mode && (env_requested || uid == 0)
 }
 
 /// Shorten a caption to what a column `width` logical px wide can show, breaking at
 /// a word boundary.
 ///
 /// The fingerprint column's captions are arbitrary-length strings from PAM, fprintd
 /// and D-Bus errors (`No reader: <zbus error>`). The paint API clips to a rect, and a
 /// clip rect is not a layout strategy — it cuts mid-word and gives no hint that
 /// anything is missing. There is no cheap shaping call here to measure exactly, so the
 /// budget comes from the advance observed at this size (~4.15 px/char at 9pt) and is
 /// deliberately a few characters short: erring low only moves the ellipsis earlier.
 ///
 /// The width is a parameter because the column is sized from the window — it was a
 /// hardcoded 220px back when the dialog drew a fixed-size card inside itself.
 fn fit_column(text: &str, width: f32) -> String {
     const PX_PER_CHAR: f32 = 4.15;
     let max_chars = ((width / PX_PER_CHAR) as usize).max(8);
     if text.chars().count() <= max_chars {
         return text.to_string();
     }
     let head: String = text.chars().take(max_chars - 1).collect();
     let cut = head.rfind(' ').unwrap_or(head.len());
     format!("{}…", head[..cut].trim_end())
 }
 
 /// A toolkit color as the `[u8; 3]` the text prims take.
 fn text_rgb(c: [f32; 4]) -> [u8; 3] {
     [
         (c[0] * 255.0).round().clamp(0.0, 255.0) as u8,
         (c[1] * 255.0).round().clamp(0.0, 255.0) as u8,
         (c[2] * 255.0).round().clamp(0.0, 255.0) as u8,
     ]
 }
 
 /// PAM service backing the standalone password check. Polkit mode never reaches it:
 /// `polkit-agent-helper-1` runs its own `polkit-1` service inside the helper process.
 const PAM_SERVICE: &str = "system-local-login";
 
 /// Who we authenticate as when nothing more specific is known.
 ///
 /// The passwd database is asked first and `$USER` is only a fallback, which is the
 /// opposite of what this used to do: a user unit's environment is whatever
 /// `systemctl --user import-environment` was told to carry, so `$USER` can simply be
 /// absent here — and the old code answered that by authenticating as a login name
 /// hardcoded to this developer's machine.
 fn current_username() -> Option<String> {
     users::get_current_username()
         .map(|name| name.to_string_lossy().into_owned())
         .or_else(|| std::env::var("USER").ok())
         .filter(|name| !name.is_empty())
 }
 
 /// A polkit cookie as the log shows it: its first few characters, enough to
 /// tell requests apart in a log, never the whole one-time token. Until
 /// 2026-10-02 every request's full cookie went into the journal at info.
 fn cookie_tag(cookie: &str) -> String {
     let head: String = cookie.chars().take(6).collect();
     if head.len() < cookie.len() { format!("{head}…") } else { head }
 }
 
 /// Consume a pending cancellation for `cookie`, reporting whether one was there.
 fn take_cancelled(cookie: &str) -> bool {
     let mut st = COOKIES.lock().unwrap();
     match st.cancelled.iter().position(|c| c == cookie) {
         Some(pos) => {
             st.cancelled.remove(pos);
             true
         }
         None => false,
     }
 }
 
 struct AuthenticatorApp {
     password_box: Handle<cce_ui::widget::Adapted<TextBox>>,
     verify_btn: Handle<cce_ui::widget::Adapted<cce_ui::widget::Button>>,
     cancel_btn: Handle<cce_ui::widget::Adapted<cce_ui::widget::Button>>,
     fingerprint_btn: Handle<cce_ui::widget::Adapted<cce_ui::widget::Button>>,
     
     status_msg: String,
     status_is_error: bool,
     status_is_success: bool,
     
     fingerprint_msg: String,
     fingerprint_active: bool,
     fingerprint_success: bool,
     /// Whether the fingerprint button does anything if pressed. In polkit mode it
     /// does not: `pam_fprintd` inside the helper owns the reader, and whether it is
     /// even in the stack is PAM's business, not ours — so the column stays dimmed
     /// and unclaimed until a PAM message shows it is asking for a finger.
     fingerprint_interactive: bool,
     
     rx_auth: std::sync::mpsc::Receiver<AuthResult>,
     tx_auth: std::sync::mpsc::Sender<AuthResult>,
     
     width: f32,
     height: f32,
     
     simulate_mode: bool,
     glow_timer: f32,
     
     polkit_mode: bool,
     helper_stdin: Option<std::process::ChildStdin>,
     shared_child: Option<Arc<Mutex<Option<std::process::Child>>>>,
     /// Identity and cookie of the in-flight polkit request, kept so a failed
     /// attempt can start a fresh helper — see `RETRIES`.
     username: String,
     cookie: String,
     retries_left: u32,
     sender: calloop::channel::Sender<AppMessage>,
     ui_context: cce_ui::context::UiContext,
 }
 
 /// Extra helper runs allowed after the first attempt fails. `polkit-agent-helper-1`
 /// runs one PAM conversation and exits, so a retry means a new process; bounding the
 /// count also keeps a helper that fails *instantly* (a cookie polkitd no longer
 /// recognises) from spawning in a tight loop.
 const RETRIES: u32 = 2;
 
 /// Start `polkit-agent-helper-1` for one attempt, returning its stdin and a handle
 /// the Cancel path can kill. The reader thread translates the helper's PAM protocol
 /// into AppMessages and reports the exit status as the attempt's verdict.
 fn spawn_helper(
     username: &str,
     cookie: &str,
     sender: &calloop::channel::Sender<AppMessage>,
 ) -> std::io::Result<(std::process::ChildStdin, Arc<Mutex<Option<std::process::Child>>>)> {
     let mut child = std::process::Command::new("/usr/lib/polkit-1/polkit-agent-helper-1")
         .arg(username)
         .arg(cookie)
         .stdin(std::process::Stdio::piped())
         .stdout(std::process::Stdio::piped())
         .stderr(std::process::Stdio::inherit())
         .spawn()?;
 
     let missing = |what| std::io::Error::new(std::io::ErrorKind::Other, what);
     let stdin = child.stdin.take().ok_or_else(|| missing("helper stdin"))?;
     let stdout = child.stdout.take().ok_or_else(|| missing("helper stdout"))?;
 
     let child_arc = Arc::new(Mutex::new(Some(child)));
     let reader_arc = child_arc.clone();
     let sender = sender.clone();
 
     std::thread::spawn(move || {
         use std::io::BufRead;
         let reader = std::io::BufReader::new(stdout);
         for line in reader.lines().map_while(Result::ok) {
             if let Some(prompt) = line.strip_prefix("PAM_PROMPT_ECHO_OFF ") {
                 let _ = sender.send(AppMessage::PromptReceived(prompt.to_string(), false));
             } else if let Some(prompt) = line.strip_prefix("PAM_PROMPT_ECHO_ON ") {
                 let _ = sender.send(AppMessage::PromptReceived(prompt.to_string(), true));
             } else if let Some(msg) = line.strip_prefix("PAM_ERROR_MSG ") {
                 let _ = sender.send(AppMessage::StatusReceived(msg.to_string(), true));
             } else if let Some(msg) = line.strip_prefix("PAM_TEXT_INFO ") {
                 let _ = sender.send(AppMessage::StatusReceived(msg.to_string(), false));
             }
         }
 
         // Cancel takes the child to kill it; finding None here means this attempt
         // was abandoned deliberately and owes no verdict.
         let mut lock = reader_arc.lock().unwrap();
         if let Some(mut child) = lock.take() {
             drop(lock);
             match child.wait() {
                 Ok(status) if status.success() => {
                     let _ = sender.send(AppMessage::AuthDone(AuthResult::Success));
                 }
                 _ => {
                     let _ = sender.send(AppMessage::AuthDone(AuthResult::Failure(
                         "Authentication failed".to_string(),
                     )));
                 }
             }
         }
     });
 
     Ok((stdin, child_arc))
 }
 
 impl Application for AuthenticatorApp {
     type Message = AppMessage;
 
     fn ui_context(&self) -> Option<&cce_ui::context::UiContext> {
         Some(&self.ui_context)
     }
 
     fn create(sender: cce_ui::engine::AppSender<Self::Message>) -> Self {
         // The app keeps calloop's sender; `AppSender` converts into it.
         let sender: calloop::channel::Sender<Self::Message> = sender.into();
         let password_box = TextBox::new(String::new())
             .with_password(true)
             .with_label("PASSWORD");
             
         let btn_h = cce_ui::layout::button_height();
         let verify_btn = Button::new(0.0, 0.0, 100.0, btn_h).with_label("Verify");
         let cancel_btn = Button::new(0.0, 0.0, 100.0, btn_h).with_label("Cancel");
         let mut fingerprint_btn = Button::new(0.0, 0.0, 120.0, 120.0).with_label("Scan");
         
         let (tx_auth, rx_auth) = std::sync::mpsc::channel();
         
         let active_req = ACTIVE_REQUEST.lock().unwrap();
         let polkit_mode = active_req.is_some();
         
         let mut helper_stdin = None;
         let mut shared_child = None;
         let mut status_msg = "Authenticate using password or fingerprint".to_string();
         // Simulation stands in for PAM, and a simulated success answers polkitd with
         // Ok(()) — i.e. grants the privileged action having checked no credential at
         // all. So it is gated on the unsafe state (a real request is in flight), not
         // on how simulation was asked for: with a request present it is off, full
         // stop, whatever CCE_AUTH_SIMULATE says. The password and fingerprint paths
         // below exclude it a second time on the same condition.
         let simulate_mode = simulate_allowed(
             polkit_mode,
             std::env::var("CCE_AUTH_SIMULATE").is_ok(),
             users::get_current_uid(),
         );
 
         let mut username = String::new();
         let mut cookie = String::new();
 
         // In polkit mode the button reports the reader rather than driving it, so it
         // should not read as something to press.
         if polkit_mode {
             fingerprint_btn.set_label("Reader");
         }
 
         if let Some(ref req) = *active_req {
             if std::env::var("CCE_AUTH_SIMULATE").is_ok() {
                 log::warn!(
                     "CCE_AUTH_SIMULATE is set and is being IGNORED: a real polkit request is in flight"
                 );
             }
             status_msg = req.message.clone();
             username = req.username.clone();
             cookie = req.cookie.clone();
 
             match spawn_helper(&username, &cookie, &sender) {
                 Ok((stdin, child)) => {
                     helper_stdin = Some(stdin);
                     shared_child = Some(child);
                 }
                 Err(e) => {
                     status_msg = format!("Failed to spawn helper: {}", e);
                 }
             }
         }
 
         // Store active sender for Cancel D-Bus calls
         *ACTIVE_SENDER.lock().unwrap() = Some(sender.clone());
 
         // A cancel that landed while this window was starting found no sender to
         // deliver to; claim it now that there is one.
         if polkit_mode && take_cancelled(&cookie) {
             log::info!("cookie {} was cancelled while its window was starting", cookie_tag(&cookie));
             let _ = sender.send(AppMessage::Cancel);
         }
 
         // The context owns the widgets; the app keeps their handles.
         let mut ui_context = cce_ui::context::UiContext::new();
         let mut app = Self {
             password_box: ui_context.insert(password_box),
             verify_btn: ui_context.insert(verify_btn),
             cancel_btn: ui_context.insert(cancel_btn),
             fingerprint_btn: ui_context.insert(fingerprint_btn),
             
             status_msg,
             status_is_error: false,
             status_is_success: false,
             
             fingerprint_msg: if polkit_mode {
                 "Handled by PAM — follow the prompt".to_string()
             } else {
                 "Fingerprint scanner ready".to_string()
             },
             fingerprint_active: false,
             fingerprint_success: false,
             fingerprint_interactive: !polkit_mode,
             
             rx_auth,
             tx_auth,
             
             width: 800.0,
             height: 600.0,
             
             simulate_mode,
             glow_timer: 0.0,
             
             polkit_mode,
             helper_stdin,
             shared_child,
             username,
             cookie,
             retries_left: RETRIES,
             sender: sender.clone(),
             ui_context,
         };
         
         let tx = app.tx_auth.clone();
         if app.simulate_mode {
             app.status_msg = "SIMULATION MODE: use password 'password' or click fingerprint".to_string();
             app.fingerprint_msg = "Click fingerprint sensor to scan".to_string();
             let tx_clone = tx.clone();
             tokio::spawn(async move {
                 tokio::time::sleep(std::time::Duration::from_secs(2)).await;
                 log::info!("Auto-authenticating in simulation mode...");
                 let _ = tx_clone.send(AuthResult::Success);
             });
         } else if !app.polkit_mode {
             let Some(username) = current_username() else {
                 app.fingerprint_msg = "Cannot determine the current user".to_string();
                 return app;
             };
             tokio::spawn(async move {
                 if let Err(e) = run_dbus_fingerprint(username, tx.clone()).await {
                     let _ = tx.send(AuthResult::FingerprintStatus(format!("No reader: {}", e)));
                     tokio::time::sleep(std::time::Duration::from_millis(1500)).await;
                     let _ = tx.send(AuthResult::FingerprintStatus("Simulation mode active. Click icon to verify.".to_string()));
                 }
             });
         } else {
             // In Polkit mode, pam_fprintd.so running inside polkit-agent-helper-1
             // will handle claiming and verifying the fingerprint reader natively.
         }
         
         app
     }
 
     fn settings(&self) -> WindowSettings {
         WindowSettings {
             title: "CCE Authenticator".to_string(),
             app_id: "cce-authenticator".to_string(),
             width: 640,
             // Sized to the content now that there is no inset card: title band,
             // two column wells, status shelf. At 400 the wells ran ~70px past
             // anything in them and the dialog read as half empty.
             height: 360,
             fullscreen: false,
             min_size: Some((560, 340)),
         }
     }
 
     /// A session modal is a utility window: two fixed columns and a status
     /// shelf, nothing worth resizing, and nothing it should ever inherit.
     ///
     /// The size matters more here than for an ordinary tool. The compositor
     /// restores a saved size per app_id over the client's request, so before
     /// this the prompt came back at whatever it was last left at — and a
     /// prompt is not something the user chose to open at a size, it is
     /// something that appeared. Utility means no geometry is saved for it, so
     /// none can be restored: every prompt is the shape this dialog asks for.
     /// It also drops the resize affordance (the whole border band moves it)
     /// and keeps the window out of the overview displacement.
     ///
     /// Placement stays the compositor's — `Window::try_center_on_view` centers
     /// this app_id on the current view, and it is exempt from Utility's
     /// self-sizing for position only.
     fn utility(&self) -> bool {
         true
     }
 
     fn update(&mut self, msg: Self::Message, needs_rebuild: &mut bool, exit: &mut bool) {
         *needs_rebuild = true;
         match msg {
             AppMessage::PasswordVerify => {
                 if self.status_is_success { return; }
                 let password = self.ui_context[self.password_box].text.clone();
                 self.status_msg = "Verifying password...".to_string();
                 self.status_is_error = false;
                 
                 // Polkit mode answers through the helper or not at all — never through
                 // the local PAM/simulation branch, which can report success on its own.
                 if self.polkit_mode {
                     match self.helper_stdin {
                         Some(ref mut stdin) => {
                             let _ = writeln!(stdin, "{}", password);
                             let _ = stdin.flush();
                             self.ui_context[self.password_box].text.clear();
                         }
                         None => {
                             self.status_msg =
                                 "No authentication helper — press Escape to cancel".to_string();
                             self.status_is_error = true;
                         }
                     }
                 } else {
                     let tx = self.tx_auth.clone();
                     let simulate = self.simulate_mode;
                     tokio::spawn(async move {
                         if simulate {
                             tokio::time::sleep(std::time::Duration::from_millis(800)).await;
                             if password == "password" || password.is_empty() {
                                 let _ = tx.send(AuthResult::Success);
                             } else {
                                 let _ = tx.send(AuthResult::Failure("Invalid password (use 'password' or empty)".to_string()));
                             }
                         } else {
                             let Some(username) = current_username() else {
                                 let _ = tx.send(AuthResult::Failure(
                                     "Cannot determine the current user".to_string(),
                                 ));
                                 return;
                             };
                             match tokio::task::spawn_blocking(move || run_pam_auth(&username, &password)).await {
                                 Ok(Ok(())) => {
                                     let _ = tx.send(AuthResult::Success);
                                 }
                                 Ok(Err(e)) => {
                                     let _ = tx.send(AuthResult::Failure(e));
                                 }
                                 Err(_) => {
                                     let _ = tx.send(AuthResult::Failure("Auth task panicked".to_string()));
                                 }
                             }
                         }
                     });
                 }
             }
             AppMessage::FingerprintScanStart => {
                 if self.fingerprint_success || self.status_is_success { return; }
                 if self.polkit_mode {
                     // PAM fprintd handles the hardware reader natively in Polkit mode
                     return;
                 }
                 self.fingerprint_active = true;
                 self.fingerprint_msg = "Place finger on reader...".to_string();
                 
                 let tx = self.tx_auth.clone();
                 let simulate = self.simulate_mode;
                 
                 tokio::spawn(async move {
                     if simulate {
                         tokio::time::sleep(std::time::Duration::from_millis(1500)).await;
                         let _ = tx.send(AuthResult::Success);
                     } else {
                         let Some(username) = current_username() else {
                             let _ = tx.send(AuthResult::FingerprintStatus(
                                 "Cannot determine the current user".to_string(),
                             ));
                             return;
                         };
                         if let Err(e) = run_dbus_fingerprint(username, tx.clone()).await {
                             let _ = tx.send(AuthResult::FingerprintStatus(format!("Scan error: {}", e)));
                         }
                     }
                 });
             }
             AppMessage::Cancel => {
                 if let Some(ref shared_child) = self.shared_child {
                     if let Some(mut child) = shared_child.lock().unwrap().take() {
                         let _ = child.kill();
                         // `kill` only signals — Rust never reaps on drop — and taking the
                         // child here means the reader thread won't wait() on it either, so
                         // without this every cancelled prompt left a zombie for the life of
                         // the session. Reaped off-thread because this daemon must never
                         // wedge on a wait: it is the session's only polkit agent.
                         std::thread::spawn(move || {
                             let _ = child.wait();
                         });
                     }
                 }
                 *exit = true;
             }
             AppMessage::PromptReceived(prompt, _echo) => {
                 self.ui_context[self.password_box].set_label(&prompt);
                 self.ui_context[self.password_box].text.clear();
             }
             AppMessage::StatusReceived(msg, is_error) => {
                 self.status_msg = msg.clone();
                 self.status_is_error = is_error;
                 self.status_is_success = false;
                 if msg.to_lowercase().contains("finger") {
                     // PAM's wording is a whole sentence naming the finger and the
                     // reader, and the wide status line above already carries it
                     // verbatim. Repeating it inside the narrow column printed it
                     // twice and cut the copy mid-word ("…on the fingerprint read"),
                     // so the column reports the state instead.
                     self.fingerprint_active = true;
                     self.fingerprint_msg = "Waiting for finger…".to_string();
                 }
             }
             AppMessage::AuthDone(res) => {
                 log::debug!("AppMessage::AuthDone received: {:?}", res);
                 match res {
                     AuthResult::Success => {
                         self.status_is_success = true;
                         self.status_is_error = false;
                         self.fingerprint_success = true;
                         self.fingerprint_active = false;
                         self.status_msg = "Authentication Successful!".to_string();
                         self.fingerprint_msg = "Authenticated".to_string();
                         
                         if self.polkit_mode {
                             log::info!("AuthResult::Success in Polkit mode. Sending Ok to tx_result and spawning exit timer.");
                             if let Some(req) = ACTIVE_REQUEST.lock().unwrap().take() {
                                 let _ = req.tx_result.send(Ok(()));
                             } else {
                                 log::warn!("WARNING: ACTIVE_REQUEST was None inside AuthDone(Success)!");
                             }
                             let tx = self.tx_auth.clone();
                             tokio::spawn(async move {
                                 log::debug!("Exit timer task spawned, sleeping 800ms...");
                                 tokio::time::sleep(std::time::Duration::from_millis(800)).await;
                                 log::debug!("Exit timer slept 800ms. Sending ExitWindow to tx.");
                                 let _ = tx.send(AuthResult::ExitWindow);
                             });
                         } else {
                             log::info!("AuthResult::Success in standalone mode. Exiting process in 1000ms.");
                             tokio::spawn(async move {
                                 tokio::time::sleep(std::time::Duration::from_millis(1000)).await;
                                 std::process::exit(0);
                             });
                         }
                     }
                     AuthResult::ExitWindow => {
                         log::info!("AuthResult::ExitWindow received in update. Setting exit = true.");
                         *exit = true;
                     }
                     AuthResult::Failure(err) => {
                         log::error!("AuthResult::Failure received: {}", err);
                         self.status_is_error = true;
                         self.status_msg = err;
 
                         // The helper has exited — it runs one PAM conversation per
                         // process — so the stdin we still hold is a closed pipe and
                         // Verify would write into nothing. A retry needs a fresh one.
                         if self.polkit_mode {
                             self.helper_stdin = None;
                             self.shared_child = None;
                             self.ui_context[self.password_box].text.clear();
 
                             if self.retries_left == 0 {
                                 log::warn!("no attempts left for cookie {}", cookie_tag(&self.cookie));
                                 self.status_msg =
                                     format!("{} — press Escape to cancel", self.status_msg);
                             } else {
                                 self.retries_left -= 1;
                                 match spawn_helper(&self.username, &self.cookie, &self.sender) {
                                     Ok((stdin, child)) => {
                                         log::info!(
                                             "restarted helper for another attempt ({} left after this)",
                                             self.retries_left
                                         );
                                         self.helper_stdin = Some(stdin);
                                         self.shared_child = Some(child);
                                     }
                                     Err(e) => {
                                         log::error!("could not restart helper: {}", e);
                                         self.status_msg =
                                             format!("Could not restart helper: {}", e);
                                     }
                                 }
                             }
                         }
                     }
                     AuthResult::FingerprintStatus(status) => {
                         log::info!("AuthResult::FingerprintStatus received: {}", status);
                         if !self.polkit_mode
                             && (status.contains("Simulation mode active")
                                 || status.contains("No reader"))
                         {
                             self.simulate_mode = true;
                         }
                         self.fingerprint_msg = status;
                     }
                 }
             }
         }
     }
 
     /// `tick` drains `rx_auth`, a std channel the runner cannot see; without
     /// this the password verdict would wait for the next unrelated event.
     fn idle_poll_interval(&self) -> Option<std::time::Duration> {
         Some(std::time::Duration::from_millis(50))
     }
 
     fn tick(&mut self, dt: f32, needs_rebuild: &mut bool) {
         while let Ok(res) = self.rx_auth.try_recv() {
             let _ = self.sender.send(AppMessage::AuthDone(res));
         }
         
         if self.fingerprint_active {
             self.glow_timer += dt * 4.0;
             *needs_rebuild = true;
         }
     }
 
     fn display_list(&mut self, size: LogicalSize, scale: f64) -> Option<cce_ui::scene::paint::DisplayList> {
         // Id-rooted router: dispatch roots resolve through the registry — keep the
         // four roots' registrations fresh each frame (idempotent; the dialog assembles
         // its frame by hand, so nothing else registers them).
         {
         }
         // Phase 6ag single paint path: the whole frame — card, columns, widgets, and all
         // text — is this one list. NOTE this migration is a FIX, not a match: the app's old
         // FontSystem shaped buffers whose fontdb face IDs did not resolve in the engine's
         // render FontSystem, so ALL of this dialog's text was silently invisible (the 6e
         // class). Shaped as display-list Text prims through the engine cache, it renders.
         use cce_ui::scene::layout::Rect;
         cce_ui::scale::set_scale_factor(scale as f32);
         let sw = size.width as f32;
         let sh = size.height as f32;
         self.width = sw;
         self.height = sh;
 
         let mut pc = cce_ui::scene::paint::PaintCtx::new();
 
         // ── The window plate ──
         //
         // The window IS the dialog: the standard root plate (cce-ui
         // `PlateSpec::window`), one lit slab whose rolled perimeter reads as
         // the physical edge the silhouette already implies. It replaced a
         // dimmed surface with a 540x320 "card" outlined in four square quads.
         pc.root_plate(sw, sh);
 
         // ── Layout ──
         //
         // Spacing comes off the toolkit's ladder, never a literal: the window
         // inset for anything against the window edge, the root gap between the
         // dialog's parts (the two columns, the wells and the status band), the
         // pane rung inside each well.
         let pad = cce_ui::layout::root_plate_inset();
         let status_h = 40.0f32;
         let gutter = cce_ui::layout::root_plate_gap();
         let caption_h = 22.0f32;
         // TODO(style): the title row — a 15pt line plus its run down to the
         // captions folded into one number; not a rung, so it stays a height.
         let title_h = 34.0f32;
 
         let status_y = sh - status_h;
         let content_y = pad + title_h;
         let col_w = ((sw - pad * 2.0 - gutter) / 2.0).max(140.0);
         let fp_col_x = pad;
         let pw_col_x = pad + col_w + gutter;
         let well_y = content_y + caption_h;
         let well_h = (status_y - gutter - well_y).max(90.0);
         let well_r = cce_ui::layout::plate_corner_radius();
         let well_depth = cce_ui::layout::bevel_width().min(well_h * 0.2);
 
         // Both columns are wells carved into the plate — the captions label a real
         // recess instead of floating over an undifferentiated fill.
         for x in [fp_col_x, pw_col_x] {
             pc.recess(
                 Rect { x, y: well_y, width: col_w, height: well_h },
                 (well_r, well_r, well_r, well_r),
                 well_depth,
             );
         }
 
         // The status line gets the statusbar treatment: a band carved across the foot
         // of the plate, top wall only so the seam reads as a shelf rather than a box
         // inset from edges the window already rounds.
         pc.recess_edges(
             Rect { x: 0.0, y: status_y, width: sw, height: status_h },
             (0.0, 0.0, 0.0, 0.0),
             cce_ui::layout::bar_wall_width(),
             (true, false, false, false),
         );
 
         // ── Widget geometry ──
         //
         // The two columns fill their wells differently because their contents differ:
         // the reader is one target, so it centers; the password column is a form, so
         // it runs input at the top and actions at the foot.
         // Each well is the dialog's pane: its rim-to-content inset and the gap
         // between the things inside it are the pane rung.
         let inset = cce_ui::layout::plate_padding();
         let gap = cce_ui::layout::plate_gap();
         let cap_h = 34.0f32; // two lines at 9pt, the longest PAM/fprintd captions
         // TODO(style): 78 is the vertical room the caption block reserves under
         // the reader (gap + cap_h + slack), pinned as one number when the reader
         // was sized; a size, not a rung.
         let fp_btn_w = 150.0f32.min(col_w - inset * 2.0).min(well_h - 78.0).max(64.0);
         let fp_btn_h = fp_btn_w;
         let fp_btn_x = fp_col_x + (col_w - fp_btn_w) / 2.0;
         // Target + caption ride as one block centered in the well. Top-anchored, the
         // block left a third of the column empty under it and the column read as
         // unfinished rather than as a target with room around it.
         let fp_block_h = fp_btn_h + gap + cap_h;
         let fp_btn_y = well_y + ((well_h - fp_block_h) / 2.0).max(inset);
         self.ui_context[self.fingerprint_btn].set_rect(fp_btn_x, fp_btn_y, fp_btn_w, fp_btn_h);
 
         // The reader's state color rides on the widget so the plate path paints it.
         // It used to be a quad drawn UNDER the widget loop's `quad(w.rect(), w.color())`
         // on the identical rect — so every state (the success accent, the scanning
         // glow, the dimmed-inert fill) was overpainted by the button's flat default
         // and none of them ever reached the screen.
         self.ui_context[self.fingerprint_btn].bg = Some(if self.fingerprint_success {
             ACCENT
         } else if self.fingerprint_active {
             let alpha = 0.4 + 0.3 * self.glow_timer.sin();
             [0.16, 0.41, 0.18, alpha]
         } else if self.fingerprint_interactive {
             TOGGLE_OFF
         } else {
             // PAM owns the reader here, and the click handler drops presses on the
             // floor — so don't paint this like something that responds to one.
             TOGGLE_INERT
         });
 
         let pw_inner_x = pw_col_x + inset;
         let pw_inner_w = col_w - inset * 2.0;
         // TODO(style): 40 places the entry below the well's top lip — more than
         // the pane inset, less than a control gap; a placement, not a rung.
         // The rect carries the PASSWORD label's strip above the box itself.
         let pw_box_h = cce_ui::layout::textbox_height() + self.ui_context[self.password_box].label_strip();
         self.ui_context[self.password_box].set_rect(pw_inner_x, well_y + 40.0, pw_inner_w, pw_box_h);
 
         // The two actions split the column. They were a fixed 100px, which "Verify
         // Password" overran on both sides at the DE's 14pt control font — the label
         // is "Verify" now, and the width follows the column instead of a constant.
         let btn_w = ((pw_inner_w - gap) / 2.0).max(72.0);
         let btn_h = cce_ui::layout::button_height();
         let btn_y = well_y + well_h - inset - btn_h;
         self.ui_context[self.verify_btn].set_rect(pw_inner_x, btn_y, btn_w, btn_h);
         self.ui_context[self.cancel_btn].set_rect(pw_inner_x + pw_inner_w - btn_w, btn_y, btn_w, btn_h);
 
         // Run each control through the real paint walk, which is how every other cce
         // app draws its widgets: the widget's own `Paint` impl, so a Button emits the
         // sunken `inset_plate` its `raised` style means and a TextBox its recessed
         // well, along with hover/press/focus state and its text.
         //
         // NOT `append_widget_plate` — that is the designer's escape hatch, and it
         // resolves a plate through `plate_bevel()`/`solid_border()`, neither of which
         // `Adapted` forwards from `Button`. Every control came out as a bevel filled
         // with the configured button face, which this DE sets to #00000000: invisible.
         for w in self.widgets_iter() {
             cce_ui::scene::painter::paint_root_into(&self.ui_context, w, &mut pc);
         }
 
         if self.fingerprint_active {
             // style: deliberate — the scan line's 10px stand-off inside the
             // reader target is the glyph's own geometry, not a layout gap.
             let scan_y = fp_btn_y + 10.0
                 + (50.0 + 50.0 * self.glow_timer.sin()).clamp(0.0, fp_btn_h - 20.0);
             pc.quad(
                 Rect { x: fp_btn_x + 10.0, y: scan_y, width: fp_btn_w - 20.0, height: 2.0 },
                 [0.30, 0.90, 0.32, 0.8],
             );
         }
 
         // ── Text ──
         let caption = cce_ui::color::control_label_color_detached_u8();
         pc.text_with(
             "CCE AUTHENTICATOR".to_string(),
             pad,
             pad,
             15.0,
             text_rgb(cce_ui::color::TEXT_HEADER),
             None,
             None,
         );
         pc.text_with("FINGERPRINT AUTHENTICATION".to_string(), fp_col_x, content_y, 10.0, caption, None, None);
         pc.text_with("PASSWORD AUTHENTICATION".to_string(), pw_col_x, content_y, 10.0, caption, None, None);
 
         let fp_msg_color = if self.fingerprint_success {
             [0xa0, 0xee, 0xa0]
         } else if self.fingerprint_interactive || self.fingerprint_active {
             text_rgb(cce_ui::color::TEXT_FG)
         } else {
             caption
         };
         let fp_msg_x = fp_col_x + inset;
         let fp_msg_w = col_w - inset * 2.0;
         let fp_msg_y = fp_btn_y + fp_btn_h + gap;
         pc.text_with(
             fit_column(&self.fingerprint_msg, fp_msg_w),
             fp_msg_x,
             fp_msg_y,
             9.0,
             fp_msg_color,
             None,
             Some([fp_msg_x, fp_msg_y, fp_msg_x + fp_msg_w, fp_msg_y + cap_h]),
         );
 
         let status_color = if self.status_is_success {
             [0xa0, 0xee, 0xa0]
         } else if self.status_is_error {
             [0xee, 0x5c, 0x5c]
         } else {
             text_rgb(cce_ui::color::TEXT_FG)
         };
         let status_text_y = status_y + (status_h - 12.0) / 2.0;
         pc.text_with(
             self.status_msg.clone(),
             pad,
             status_text_y,
             10.0,
             status_color,
             None,
             Some([pad, status_y, sw - pad, sh]),
         );
 
         Some(pc.finish())
     }
 
     fn display_list_text(&self) -> bool {
         true
     }
 
     fn handle_pointer_move(&mut self, pos: LogicalPosition, needs_rebuild: &mut bool) {
         // The shared context menu (the password box's) gets the pointer to itself
         // while open: its row highlight.
         if cce_ui::widget::context_menu::is_visible() {
             if cce_ui::widget::context_menu::cursor_moved(pos.x, pos.y) {
                 *needs_rebuild = true;
             }
             return;
         }
         // Routed dispatch (6bd shrink): one Event per widget root through the router.
         let mv = cce_ui::widget::Event::PointerMove { x: pos.x, y: pos.y, local_x: pos.x, local_y: pos.y };
         let ctx = &mut self.ui_context;
         // `bg` is deliberately absent: `ContentBg::hit` is unconditionally false, so it
         // can never consume a pointer event, and it is the one root this dialog paints
         // without registering — routing to it logged "unregistered/stale root … event
         // dropped" on every motion event for the life of the daemon.
         if ctx.propagate_event(&mv, self.password_box.id()) { *needs_rebuild = true; }
         if ctx.propagate_event(&mv, self.verify_btn.id()) { *needs_rebuild = true; }
         if ctx.propagate_event(&mv, self.cancel_btn.id()) { *needs_rebuild = true; }
         if ctx.propagate_event(&mv, self.fingerprint_btn.id()) { *needs_rebuild = true; }
     }
 
     fn handle_mouse_input(&mut self, button: MouseButton, state: ElementState, pos: LogicalPosition, needs_rebuild: &mut bool) -> Option<Self::Message> {
         let (lx, ly) = (pos.x, pos.y);
 
         // The shared context menu a right-click on the password box opens takes
         // every click while open: a row runs, a press anywhere else dismisses it.
         // The toolkit leaves this routing to the app; without it the menu could
         // not be closed by clicking outside it, and its rows did nothing.
         if cce_ui::widget::context_menu::is_visible() {
             if cce_ui::widget::context_menu::mouse_input(button, state, lx, ly, Some(&mut self.ui_context)) {
                 *needs_rebuild = true;
             }
             return None;
         }
 
         let ev = cce_ui::widget::Event::MouseButton { button, state, x: lx, y: ly, local_x: lx, local_y: ly };
 
         if { let root = self.verify_btn.id(); self.ui_context.propagate_event(&ev, root) } {
             *needs_rebuild = true;
         }
         if self.ui_context[self.verify_btn].take_click() {
             return Some(AppMessage::PasswordVerify);
         }
         
         if { let root = self.cancel_btn.id(); self.ui_context.propagate_event(&ev, root) } {
             *needs_rebuild = true;
         }
         if self.ui_context[self.cancel_btn].take_click() {
             return Some(AppMessage::Cancel);
         }
         
         if { let root = self.fingerprint_btn.id(); self.ui_context.propagate_event(&ev, root) } {
             *needs_rebuild = true;
         }
         if self.ui_context[self.fingerprint_btn].take_click() {
             return Some(AppMessage::FingerprintScanStart);
         }
         
         let hit = self.ui_context[self.password_box].hit_test(lx, ly, &self.ui_context);
         if state == ElementState::Pressed && !hit {
             self.ui_context[self.password_box].unfocus();
         }
         if self.ui_context.propagate_event(&ev, self.password_box.id()) {
             *needs_rebuild = true;
         }
         
         None
     }
 
     fn handle_mouse_wheel(&mut self, _delta: &MouseScrollDelta, _pos: LogicalPosition, _needs_rebuild: &mut bool) {}
 
     fn handle_key_input(&mut self, event: &KeyEvent, needs_rebuild: &mut bool) -> Option<Self::Message> {
         if event.state == ElementState::Pressed && !event.repeat {
             if let Key::Named(NamedKey::Tab) = event.logical_key {
                 if self.ui_context[self.password_box].focused(&self.ui_context) {
                     self.ui_context[self.password_box].unfocus();
                     self.ui_context[self.verify_btn].focus();
                 } else if self.ui_context[self.verify_btn].focused(&self.ui_context) {
                     self.ui_context[self.verify_btn].unfocus();
                     self.ui_context[self.cancel_btn].focus();
                 } else {
                     self.ui_context[self.cancel_btn].unfocus();
                     self.ui_context[self.password_box].focus();
                 }
                 *needs_rebuild = true;
                 return None;
             }
             
             if let Key::Named(NamedKey::Escape) = event.logical_key {
                 return Some(AppMessage::Cancel);
             }
             
             if let Key::Named(NamedKey::Enter) = event.logical_key {
                 if self.ui_context[self.password_box].focused(&self.ui_context) {
                     return Some(AppMessage::PasswordVerify);
                 }
             }
         }
         
         let kev = cce_ui::widget::Event::KeyInput(event.clone());
         let root = self.password_box.id();
         if self.ui_context.propagate_event(&kev, root) {
             *needs_rebuild = true;
         }
         
         None
     }
 }
 
 impl AuthenticatorApp {
     /// The dialog's four real controls, in paint order.
     ///
     /// A full-window `ContentBg` used to lead this list. It was the flat backdrop the
     /// window plate now is, and once the widgets paint as plates it became actively
     /// destructive: `append_widget_plate` would have drawn its fill over the plate,
     /// erasing the lit edge and every carve under it.
     fn widgets_iter(&self) -> Vec<&dyn WidgetHost> {
         vec![
             &self.ui_context[self.password_box],
             &self.ui_context[self.verify_btn],
             &self.ui_context[self.cancel_btn],
             &self.ui_context[self.fingerprint_btn],
         ]
     }
 }
 
 fn run_pam_auth(username: &str, password: &str) -> Result<(), String> {
     unsafe {
         let service = PAM_SERVICE;
         let pass_c = std::ffi::CString::new(password).map_err(|e| e.to_string())?;
         
         extern "C" fn pam_conv_simple(
             _num_msg: libc::c_int,
             _msg: *mut *mut pam_sys::PamMessage,
             resp: *mut *mut pam_sys::PamResponse,
             appdata_ptr: *mut libc::c_void,
         ) -> libc::c_int {
             unsafe {
                 let password = appdata_ptr as *const libc::c_char;
                 let resp_size = std::mem::size_of::<pam_sys::PamResponse>();
                 let calloc_resp = libc::calloc(1, resp_size) as *mut pam_sys::PamResponse;
                 (*calloc_resp).resp = libc::strdup(password);
                 (*calloc_resp).resp_retcode = 0;
                 *resp = calloc_resp;
                 pam_sys::PamReturnCode::SUCCESS as libc::c_int
             }
         }
         
         let mut handle: *mut pam_sys::PamHandle = std::ptr::null_mut();
         let conv = pam_sys::PamConversation {
             conv: Some(pam_conv_simple),
             data_ptr: pass_c.as_ptr() as *mut libc::c_void,
         };
         
         let rc = pam_sys::start(service, Some(username), &conv, &mut handle);
         if rc != pam_sys::PamReturnCode::SUCCESS {
             return Err("Failed to start PAM".to_string());
         }
         
         let rc = pam_sys::authenticate(&mut *handle, pam_sys::PamFlag::NONE);
         pam_sys::end(&mut *handle, rc);
         
         if rc == pam_sys::PamReturnCode::SUCCESS {
             Ok(())
         } else {
             Err(format!("Incorrect password (PAM: {:?})", rc))
         }
     }
 }
 
 async fn run_dbus_fingerprint(username: String, tx: std::sync::mpsc::Sender<AuthResult>) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let connection = zbus::Connection::system().await?;
     
     let reply = connection.call_method(
         Some("net.reactivated.Fprint"),
         "/net/reactivated/Fprint/Manager",
         Some("net.reactivated.Fprint.Manager"),
         "GetDefaultDevice",
         &(),
     ).await?;
     
     let device_path: zbus::zvariant::OwnedObjectPath = reply.body().deserialize()?;
     let device_path_str = device_path.as_str();
     
     connection.call_method(
         Some("net.reactivated.Fprint"),
         device_path_str,
         Some("net.reactivated.Fprint.Device"),
         "Claim",
         &(username,),
     ).await?;
     
     let _ = tx.send(AuthResult::FingerprintStatus("Reader claimed. Scan finger...".to_string()));
     
     connection.call_method(
         Some("net.reactivated.Fprint"),
         device_path_str,
         Some("net.reactivated.Fprint.Device"),
         "VerifyStart",
         &("any",),
     ).await?;
     
     let mut stream = zbus::MessageStream::for_match_rule(
         zbus::MatchRule::builder()
             .msg_type(zbus::message::Type::Signal)
             .sender("net.reactivated.Fprint")?
             .interface("net.reactivated.Fprint.Device")?
             .member("VerifyStatus")?
             .path(device_path_str)?
             .build(),
         &connection,
         None,
     ).await?;
     
     while let Some(msg) = stream.next().await {
         if let Ok(msg) = msg {
             if let Ok((result, keep_going)) = msg.body().deserialize::<(String, bool)>() {
                 if result == "verify-match" {
                     let _ = tx.send(AuthResult::Success);
                     break;
                 } else if result == "verify-no-match" {
                     let _ = tx.send(AuthResult::FingerprintStatus("Failed match. Try again.".to_string()));
                 } else if result == "verify-swipe-too-short" {
                     let _ = tx.send(AuthResult::FingerprintStatus("Swipe too short. Try again.".to_string()));
                 } else {
                     let _ = tx.send(AuthResult::FingerprintStatus(format!("Retry scan: {}", result)));
                 }
                 if !keep_going {
                     break;
                 }
             }
         }
     }
     
     let _ = connection.call_method(
         Some("net.reactivated.Fprint"),
         device_path_str,
         Some("net.reactivated.Fprint.Device"),
         "Release",
         &(),
     ).await;
     
     Ok(())
 }
 
 struct PolkitAgent {
     tx_gui_req: std::sync::mpsc::Sender<GuiRequest>,
 }
 
 #[zbus::interface(name = "org.freedesktop.PolicyKit1.AuthenticationAgent")]
 impl PolkitAgent {
     async fn begin_authentication(
         &self,
         _action_id: String,
         message: String,
         _icon_name: String,
         _details: std::collections::HashMap<String, String>,
         cookie: String,
         identities: Vec<(String, std::collections::HashMap<String, zbus::zvariant::OwnedValue>)>,
     ) -> zbus::fdo::Result<()> {
         log::info!("begin_authentication called! message = {:?}, cookie = {}", message, cookie_tag(&cookie));
         let mut username = String::new();
         if let Some((kind, details)) = identities.first() {
             if kind == "unix-user" {
                 if let Some(uid_val) = details.get("uid") {
                     let uid = match uid_val.deref() {
                         zbus::zvariant::Value::U32(u) => Some(*u),
                         zbus::zvariant::Value::I32(i) => Some(*i as u32),
                         zbus::zvariant::Value::U64(u) => Some(*u as u32),
                         zbus::zvariant::Value::I64(i) => Some(*i as u32),
                         _ => None,
                     };
                     if let Some(uid) = uid {
                         if let Some(user) = users::get_user_by_uid(uid) {
                             username = user.name().to_string_lossy().into_owned();
                         }
                     }
                 }
             }
         }
         // polkit names the identity it wants authenticated. If it named one we could
         // not resolve, fall back to our own — but refuse rather than guess a name,
         // because the wrong identity here means prompting for a password that cannot
         // authorize the action.
         if username.is_empty() {
             username = current_username().ok_or_else(|| {
                 zbus::fdo::Error::Failed("no resolvable unix-user identity".to_string())
             })?;
             log::warn!("no unix-user identity in the request; falling back to {}", username);
         }
 
 
         let (tx_result, rx_result) = tokio::sync::oneshot::channel();
         let req = GuiRequest {
             username,
             message,
             cookie: cookie.clone(),
             tx_result,
         };
         
         self.tx_gui_req.send(req).map_err(|e| zbus::fdo::Error::Failed(e.to_string()))?;
         
         match rx_result.await {
             Ok(Ok(())) => Ok(()),
             Ok(Err(err)) => Err(zbus::fdo::Error::Failed(err)),
             Err(_) => Err(zbus::fdo::Error::Failed("GUI closed".to_string())),
         }
     }
 
     async fn cancel_authentication(&self, cookie: String) -> zbus::fdo::Result<()> {
         log::info!("cancel_authentication called for cookie {}", cookie_tag(&cookie));
 
         // Record the cancellation for *any* cookie we have been handed, then try to
         // deliver it. Whoever owns this cookie consumes the record: the main loop
         // before opening its window, or `new()` once it has a sender. Recording
         // unconditionally is what makes the queued and still-starting cases work.
         let is_active = {
             let mut st = COOKIES.lock().unwrap();
             if !st.cancelled.iter().any(|c| c == &cookie) {
                 st.cancelled.push(cookie.clone());
             }
             st.active.as_deref() == Some(cookie.as_str())
         };
 
         if is_active {
             let sender_lock = ACTIVE_SENDER.lock().unwrap();
             if let Some(ref sender) = *sender_lock {
                 let _ = sender.send(AppMessage::Cancel);
             }
         }
         Ok(())
     }
 }
 
 async fn get_system_session_id() -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
     if let Ok(id) = std::env::var("XDG_SESSION_ID") {
         return Ok(id);
     }
     
     if let Ok(id_str) = std::fs::read_to_string("/proc/self/sessionid") {
         let id_trimmed = id_str.trim();
         if !id_trimmed.is_empty() && id_trimmed != "4294967295" {
             return Ok(id_trimmed.to_string());
         }
     }
     
     let connection = zbus::Connection::system().await?;
     let reply: zbus::zvariant::OwnedObjectPath = connection.call_method(
         Some("org.freedesktop.login1"),
         "/org/freedesktop/login1",
         Some("org.freedesktop.login1.Manager"),
         "GetSessionByPID",
         &(std::process::id() as u32,),
     ).await?.body().deserialize()?;
     
     if let Some(pos) = reply.as_str().rfind('/') {
         let id = reply.as_str()[pos + 1..].to_string();
         let id = if id.starts_with('_') { id[1..].to_string() } else { id };
         return Ok(id);
     }
     
     Err("Session ID not found".into())
 }
 
 async fn run_polkit_agent_daemon(tx_gui_req: std::sync::mpsc::Sender<GuiRequest>) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let connection = zbus::Connection::system().await?;
     let session_id = get_system_session_id().await?;
     
     let agent = PolkitAgent { tx_gui_req };
     connection.object_server().at("/org/cce/AuthenticatorAgent", agent).await?;
     
     let mut details = std::collections::HashMap::new();
     details.insert("session-id".to_string(), zbus::zvariant::Value::from(session_id.clone()));
     let subject = (
         "unix-session".to_string(),
         details,
     );
         let object_path = zbus::zvariant::ObjectPath::try_from("/org/cce/AuthenticatorAgent")?;
     
     log::info!("Registering CCE Authenticator agent for session {}", session_id);
     connection.call_method(
         Some("org.freedesktop.PolicyKit1"),
         "/org/freedesktop/PolicyKit1/Authority",
         Some("org.freedesktop.PolicyKit1.Authority"),
         "RegisterAuthenticationAgent",
         &(subject.clone(), "en_US.UTF-8", object_path.as_str()),
     ).await?;
     log::info!("Successfully registered CCE Authenticator agent!");
     
     #[cfg(unix)]
     {
         use tokio::signal::unix::{signal, SignalKind};
         let mut sigterm = signal(SignalKind::terminate())?;
         tokio::select! {
             _ = tokio::signal::ctrl_c() => {}
             _ = sigterm.recv() => {}
         }
     }
     #[cfg(not(unix))]
     {
         let _ = tokio::signal::ctrl_c().await;
     }
     
     log::info!("Unregistering CCE Authenticator agent...");
     let _ = connection.call_method(
         Some("org.freedesktop.PolicyKit1"),
         "/org/freedesktop/PolicyKit1/Authority",
         Some("org.freedesktop.PolicyKit1.Authority"),
         "UnregisterAuthenticationAgent",
         &(subject, object_path.as_str()),
     ).await;
     
     Ok(())
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
     /// Record a cancellation the way the D-Bus handler does, reporting whether it
     /// would have been delivered to a live window.
     fn cancel(cookie: &str) -> bool {
         let mut st = COOKIES.lock().unwrap();
         if !st.cancelled.iter().any(|c| c == cookie) {
             st.cancelled.push(cookie.to_string());
         }
         st.active.as_deref() == Some(cookie)
     }
 
     fn claim(cookie: &str) {
         COOKIES.lock().unwrap().active = Some(cookie.to_string());
     }
 
     fn finish(cookie: &str) {
         let mut st = COOKIES.lock().unwrap();
         st.active = None;
         st.cancelled.retain(|c| c != cookie);
     }
 
     /// Exhaustive over the gate's inputs, because this is the one invariant whose
     /// failure grants root. Checking it live would mean standing up a working
     /// authentication bypass and confirming it doesn't fire — the test settles it
     /// without ever putting the machine in that state.
     #[test]
     fn a_live_request_vetoes_simulation() {
         for &env_requested in &[true, false] {
             for &uid in &[0u32, 1000] {
                 assert!(
                     !simulate_allowed(true, env_requested, uid),
                     "polkit mode must veto simulation (env={env_requested}, uid={uid}): \
                      a simulated success answers polkitd with Ok(()) and grants the action"
                 );
             }
         }
 
         // Outside polkit mode simulation must still work, or --standalone stops being
         // a usable test window and the veto above is untestable in practice.
         assert!(simulate_allowed(false, true, 1000), "CCE_AUTH_SIMULATE drives standalone");
         assert!(simulate_allowed(false, false, 0), "root standalone simulates without the var");
         assert!(!simulate_allowed(false, false, 1000), "no request, no var, not root: real PAM");
     }
 
     #[test]
     fn column_captions_never_cut_mid_word() {
         // Roughly the interior of a column in the default 640px-wide window.
         const W: f32 = 245.0;
 
         // The message that exposed this — clipping rendered "…on the fingerprint
         // read" — now fits whole: the column grew from a hardcoded 220px to its
         // share of the window. Asserted, because it is the reason the budget had
         // to stop being a constant.
         let pam = "Place your right middle finger on the fingerprint reader";
         assert_eq!(fit_column(pam, W), pam, "the column is wide enough for PAM's wording now");
         assert!(fit_column(pam, 220.0).ends_with('…'), "…but not at the old width");
 
         // The genuinely unbounded captions are the D-Bus errors.
         let err = "No reader: org.freedesktop.DBus.Error.ServiceUnknown: \
                    The name net.reactivated.Fprint was not provided by any .service files";
         let fitted = fit_column(err, W);
         assert!(fitted.ends_with('…'), "long captions must show they were cut");
         let kept = fitted.trim_end_matches('…');
         assert!(err.starts_with(kept), "the kept head must be a real prefix: {fitted}");
         // A word boundary means the character the cut dropped was a space — that is
         // the whole difference between this and the clip rect it replaced.
         assert_eq!(
             err[kept.len()..].chars().next(),
             Some(' '),
             "cut fell mid-word: {fitted}"
         );
 
         // Short enough to stand as-is, ellipsis included or not.
         assert_eq!(fit_column("Waiting for finger…", W), "Waiting for finger…");
         assert_eq!(fit_column("", W), "");
 
         // No spaces to break on, and multi-byte characters: must not panic or slice
         // through a char boundary.
         let unbroken = "x".repeat(200);
         assert!(fit_column(&unbroken, W).ends_with('…'));
         assert!(fit_column(&"é".repeat(200), W).ends_with('…'));
 
         // A window dragged to its minimum still has to produce something, not panic
         // on an underflowing budget — the width is a layout value now, not a constant.
         assert!(!fit_column(pam, 1.0).is_empty());
         assert!(!fit_column(pam, 0.0).is_empty());
     }
 
     /// The orderings that a single active-cookie slot got wrong. One test, run in
     /// sequence, because COOKIES is process-global.
     #[test]
     fn cancellation_survives_every_ordering() {
         // Cancel lands before the main loop claims the cookie: not deliverable, but
         // the record is waiting when the loop looks, so the window never opens.
         assert!(!cancel("early"));
         claim("early");
         assert!(take_cancelled("early"), "cancel before claim must be seen");
         finish("early");
 
         // Cancel lands after the claim but before the window has a sender. It reads
         // as deliverable, yet there is nothing to deliver to — new() consumes it.
         claim("starting");
         assert!(cancel("starting"), "cancel for the claimed cookie is active");
         assert!(take_cancelled("starting"), "new() must still find it");
         finish("starting");
 
         // Cancel for a queued cookie while another window is up. It must not be
         // mistaken for the active one, and must survive that window closing.
         claim("open");
         assert!(!cancel("queued"), "a queued cookie is not the active one");
         assert!(!take_cancelled("open"), "the open window was never cancelled");
         finish("open");
         claim("queued");
         assert!(
             take_cancelled("queued"),
             "a queued cancel must outlive the window ahead of it"
         );
         finish("queued");
 
         // Nothing left behind.
         let st = COOKIES.lock().unwrap();
         assert!(st.active.is_none());
         assert!(st.cancelled.is_empty(), "cancelled cookies leaked: {:?}", st.cancelled);
     }
 }
 
 fn main() {
     env_logger::init();
     let args: Vec<String> = std::env::args().collect();
     let standalone = args.contains(&"--standalone".to_string()) || args.contains(&"-s".to_string());
     
     // Two workers: the agent's D-Bus tasks are a handful of awaits, and a
     // runtime sized to the CPU count (20 here) parked 20 threads all session
     // for them.
     let rt = tokio::runtime::Builder::new_multi_thread()
         .worker_threads(2)
         .enable_all()
         .build()
         .expect("tokio runtime");
     let _guard = rt.enter();
     
     if standalone {
         cce_ui::engine::run::<AuthenticatorApp>();
     } else {
         let (tx_gui_req, rx_gui_req) = std::sync::mpsc::channel::<GuiRequest>();
         
         rt.spawn(async move {
             if let Err(e) = run_polkit_agent_daemon(tx_gui_req).await {
                 log::error!("Error starting Polkit agent: {}", e);
                 std::process::exit(1);
             }
         });
         
         while let Ok(req) = rx_gui_req.recv() {
             log::info!("rx_gui_req received a request for user: {}, message: {}", req.username, req.message);
             let cookie = req.cookie.clone();
 
             // Claim the cookie before checking, so a cancel racing this point either
             // finds it active (and delivers, or is consumed by `new()`) or lands in
             // `cancelled` in time to be seen right here. Requests wait their turn in
             // the channel, and polkitd may well give up on one before its turn comes.
             COOKIES.lock().unwrap().active = Some(cookie.clone());
             if take_cancelled(&cookie) {
                 log::info!("cookie {} was cancelled before its window opened", cookie_tag(&cookie));
                 COOKIES.lock().unwrap().active = None;
                 let _ = req.tx_result.send(Err("Authentication cancelled".to_string()));
                 continue;
             }
 
             *ACTIVE_REQUEST.lock().unwrap() = Some(req);
 
             log::info!("Starting cce_ui::engine::run...");
             cce_ui::engine::run::<AuthenticatorApp>();
             log::info!("cce_ui::engine::run returned/exited!");
 
             *ACTIVE_SENDER.lock().unwrap() = None;
             {
                 let mut st = COOKIES.lock().unwrap();
                 st.active = None;
                 st.cancelled.retain(|c| c != &cookie);
             }
             if let Some(req) = ACTIVE_REQUEST.lock().unwrap().take() {
                 log::info!("ACTIVE_REQUEST still present, sending Cancelled to tx_result");
                 let _ = req.tx_result.send(Err("Authentication cancelled".to_string()));
             } else {
                 log::info!("ACTIVE_REQUEST was already taken (success/done).");
             }
             log::info!("Waiting for next rx_gui_req...");
         }
     }
 }