refactor: retire the plate.bevel_width override — every roll is relief.width

`style.surface.plate.bevel_width` was the pane roll's width of its own
until this morning's one-roll-width change, then an explicit override
for the rest of the day so a config carrying it kept its look. An
override that keeps working is a second width by another name, so the
loader no longer reads it: `plate_bevel_width()` is `layout::bevel_width`
and nothing else (the getter survives as the name the plate painters
call), the Option static and its setter are gone, and a config still
carrying the key is reported by path with the retired frost keys —
`retired_frost_keys` is `retired_surface_keys` now, and its warning
names both spellings. cce-relief's Save removes the key on migration.
The two material fixtures drop it; `the_pane_roll_is_the_relief_width`
loads a config that carries it and asserts the roll did not move.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

 CLAUDE.md             | 21 +++++------
 src/bin/cce-relief.rs |  2 +-
 src/color.rs          | 99 ++++++++++++++++++++++-----------------------------
 src/scene/material.rs |  8 ++---
 4 files changed, 59 insertions(+), 71 deletions(-)

diff --git a/CLAUDE.md b/CLAUDE.md
index d627086..daf069a 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -407,7 +407,7 @@ What this buys, and where the code is heading:
   (bool)false` off. The four keys it replaced (`blur` as the switch,
   `radius`, `backdrop_compression`, `refraction`) were aliases for the rest
   of that day and are RETIRED: the loader reports one it finds
-  (`color::retired_frost_keys`, a warning naming the path) and does not read
+  (`color::retired_surface_keys`, a warning naming the path) and does not read
   it — so a config with `blur=true` and no block is sharp, and the warning
   is what says why. A material's `frost` child spells its compression
   `compression` too; its `backdrop_compression` alias went with them.
@@ -570,8 +570,7 @@ Spellings that are NOT current, and what the loader does with each:
 | `relief.height` / `.profile`, `relief.edge_height` / `.edge_profile` | aliases of `wall.*` / `edge.*`; the node wins when both are present |
 | `window_manager.bevel_width` | alias of `relief.width` |
 | `param.color` (+ top-level `plate_opacity`) | alias of `plate.pane.color`, multiplied by the opacity line |
-| `plate.bevel_width` | a legacy OVERRIDE of the roll width that still wins, reported once at load; unit-blind |
-| `plate.blur` / `.radius` / `.backdrop_compression` / `.refraction`, `frost.backdrop_compression` | RETIRED: reported by path, not read |
+| `plate.blur` / `.radius` / `.backdrop_compression` / `.refraction`, `frost.backdrop_compression`, `plate.bevel_width` | RETIRED: reported by path (`color::retired_surface_keys`), not read |
 | `relief.wall.knobs` / `edge.knobs`, `profile_knobs` / `edge_knobs` | not style: cce-relief's own state (`~/.config/cce/cce-relief/state.kdl`); read once as a seed, removed on its next Save |
 
 Where each rule is argued, by its lead-in: **Frost is one block** and
@@ -580,8 +579,8 @@ editor's knobs are not a style key** and **There is one roll width** under
 "Units" (the geometry is unit-aware, which is why they sit there); the
 `menu` block under "The context menu draws in its own popup surface".
 `prefer_relief_spellings` in `layout.rs` is the one place the alias
-precedence is decided, `color::retired_frost_keys` the one place a retired
-key is named, and cce-relief's Save is the migration for all of it: it
+precedence is decided, `color::retired_surface_keys` the one place a retired
+key is named (`retired_surface_keys`), and cce-relief's Save is the migration for all of it: it
 writes the current spellings and removes every superseded one it finds.
 
 ## The standard app — root plate, rungs, and the spacing ladder
@@ -815,11 +814,13 @@ pane plate, a bordered widget plate under relief (`append_widget_plate`, via
 width of its own — `style.surface.plate.bevel_width`, default 6 against the
 relief's 9.3 — so two pane plates in one window rolled over different widths
 depending on which painter drew them, and no single key made a pane match the
-window lip. `plate_bevel_width()` now returns the relief width; the old key is
-an explicit override for a config that still carries it (reported once at
-load, and unit-blind where the relief width resolves lengths), and the test
-`the_pane_roll_is_the_relief_width_unless_a_legacy_key_overrides_it` pins the
-fallback.
+window lip. `plate_bevel_width()` now returns the relief width and nothing
+else: the old key was an explicit override for the rest of that day (so a
+config carrying it kept its look through the change) and is RETIRED — a
+config still carrying it is reported by path with the other retired surface
+keys and the key is not read, since an override that keeps working is a
+second width by another name. `the_pane_roll_is_the_relief_width` pins it,
+and cce-relief's Save removes the key.
 
 **And the relief can leave the screen.** `scene/heightfield.rs` integrates the
 height curves the shader only differentiates and samples a frame's plates into a
diff --git a/src/bin/cce-relief.rs b/src/bin/cce-relief.rs
index 8b78b1b..7bb39a2 100644
--- a/src/bin/cce-relief.rs
+++ b/src/bin/cce-relief.rs
@@ -1169,7 +1169,7 @@ impl BevelPopup {
                 // a retired key had it read as the seed (below) and loses it
                 // here, so a config migrates on its first save.
                 let frosted = self.material_frosted;
-                let migrated = ["blur", "radius", "backdrop_compression", "refraction"]
+                let migrated = ["blur", "radius", "backdrop_compression", "refraction", "bevel_width"]
                     .iter()
                     .all(|k| cce_ui::config::remove_config_value(p, &format!("style.surface.plate.{k}")));
                 w("style.surface.relief.spec", &spec)
diff --git a/src/color.rs b/src/color.rs
index efd3a10..7e4aea2 100644
--- a/src/color.rs
+++ b/src/color.rs
@@ -659,18 +659,6 @@ fn parse_and_set_colors(content: &str) {
     if let Some(t) = val.pointer("/style/surface/plate/border_thickness").and_then(|v| v.as_f64()) {
         if let Ok(mut lock) = PLATE_BORDER_THICKNESS.write() { *lock = t as f32; }
     }
-    // The pane roll's OVERRIDE, not its width: absent (the shipped state), the
-    // roll is `style.surface.relief.width` like every other roll. Read as an
-    // Option so a key removed from config clears the override on reload.
-    {
-        let t = val.pointer("/style/surface/plate/bevel_width").and_then(|v| v.as_f64()).map(|t| t as f32);
-        if t.is_some() {
-            log::warn!(
-                "style.surface.plate.bevel_width is a legacy override: the pane roll follows style.surface.relief.width when it is unset"
-            );
-        }
-        if let Ok(mut lock) = PLATE_BEVEL_WIDTH.write() { *lock = t; }
-    }
     if let Some(c) = get_color("/style/surface/param/color") {
         if let Ok(mut lock) = PARAM_BG_COLOR.write() { *lock = c; }
         if let Ok(mut lock) = PANE_COLOR_WHOLE.write() { *lock = false; }
@@ -688,14 +676,14 @@ fn parse_and_set_colors(content: &str) {
     // keys it replaced on 2026-09-28 (`blur` as the switch, `radius`,
     // `backdrop_compression`, `refraction`) were read as aliases for the rest
     // of that day and are retired: a config still carrying one is reported
-    // (`retired_frost_keys`) and the key does nothing, because an alias that
+    // (`retired_surface_keys`) and the key does nothing, because an alias that
     // keeps working is a second spelling forever. The block is absent → not
     // frosted, which is what `blur=true` alone now amounts to; the report
     // is what tells the user why their plates went sharp.
-    let retired = retired_frost_keys(&val);
+    let retired = retired_surface_keys(&val);
     if !retired.is_empty() {
         log::warn!(
-            "retired frost keys in config: {} — spell the frost as `plate {{ frost radius= compression= refraction= }}` (or a material's `frost` child with `compression`)",
+            "retired style.surface keys in config: {} — the frost is `plate {{ frost radius= compression= refraction= }}` (a material's `frost` child spells `compression`), and every roll's width is `relief width=`",
             retired.join(", ")
         );
     }
@@ -779,14 +767,17 @@ fn parse_and_set_colors(content: &str) {
     }
 }
 
-/// The retired frost spellings a parsed config still carries, as the dotted
-/// paths a user would grep for: the four flat keys under `plate` (`blur`,
-/// `radius`, `backdrop_compression`, `refraction`) and `backdrop_compression`
-/// inside any `frost` child (the plate's, or a named material's), whose one
-/// name is `compression`. Empty for a clean config.
-pub fn retired_frost_keys(val: &serde_json::Value) -> Vec<String> {
+/// The retired `style.surface` spellings a parsed config still carries, as
+/// the dotted paths a user would grep for: the four flat frost keys under
+/// `plate` (`blur`, `radius`, `backdrop_compression`, `refraction`),
+/// `backdrop_compression` inside any `frost` child (the plate's, or a named
+/// material's), whose one name is `compression`, and `plate.bevel_width`,
+/// the pane roll's former width of its own (an override for the rest of
+/// 2026-09-28, retired that evening: every roll is `relief.width`). Empty
+/// for a clean config.
+pub fn retired_surface_keys(val: &serde_json::Value) -> Vec<String> {
     let mut found = Vec::new();
-    for k in ["blur", "radius", "backdrop_compression", "refraction"] {
+    for k in ["blur", "radius", "backdrop_compression", "refraction", "bevel_width"] {
         if val.pointer(&format!("/style/surface/plate/{k}")).is_some() {
             found.push(format!("style.surface.plate.{k}"));
         }
@@ -1835,11 +1826,6 @@ pub fn set_root_plate_statusbar_blur(b: bool) {
 static PLATE_COLOR: RwLock<Option<[f32; 4]>> = RwLock::new(Some([0.15, 0.15, 0.2, 0.95]));
 static PLATE_BORDER_COLOR: RwLock<Option<[f32; 4]>> = RwLock::new(Some([0.3, 0.3, 0.4, 1.0]));
 static PLATE_BORDER_THICKNESS: RwLock<f32> = RwLock::new(1.0);
-/// A legacy override of the pane plate's roll width
-/// (`style.surface.plate.bevel_width`); `None`, the shipped state, means the
-/// roll is [`crate::layout::bevel_width`]. See [`plate_bevel_width`].
-static PLATE_BEVEL_WIDTH: RwLock<Option<f32>> = RwLock::new(None);
-
 pub fn plate_color() -> Option<[f32; 4]> {
     load_colors_once();
     style_read(&PLATE_COLOR)
@@ -1878,17 +1864,13 @@ pub fn set_plate_border_thickness(t: f32) {
 /// pane plate rolled over different widths in one window, the designer's
 /// panes could not be made to match its own window lip by editing one key,
 /// and the edge height was expressed against a width the panes did not use.
-/// The old key survives as an explicit override for a config that still
-/// carries it, reported once at load; it is unit-blind (a bare number) where
-/// the relief width resolves lengths through the metric.
+/// The old key was an explicit override for the rest of that day and is
+/// RETIRED: a config still carrying it is reported by path
+/// (`retired_surface_keys`) and the key is not read. The getter survives
+/// as the name the plate painters call, so a caller need not know which
+/// registry key a roll is.
 pub fn plate_bevel_width() -> f32 {
-    load_colors_once();
-    style_read(&PLATE_BEVEL_WIDTH).unwrap_or_else(crate::layout::bevel_width)
-}
-
-/// Install (or with `None` clear) the legacy pane-roll override.
-pub fn set_plate_bevel_width(t: Option<f32>) {
-    style_write(&PLATE_BEVEL_WIDTH, t);
+    crate::layout::bevel_width()
 }
 
 /// How hard a frosted plate pulls its backdrop's LUMINANCE toward its own key
@@ -2238,42 +2220,47 @@ mod tests {
     }
 
     /// Rim refraction defaults OFF and clamps, like its neighbour.
-    /// The pane plates roll over the relief width — the one roll width — and
-    /// the legacy `plate.bevel_width` key is an override, not a second width.
+    /// The pane plates roll over the relief width — the one roll width —
+    /// and nothing, a loaded `plate.bevel_width` included, moves them off it.
     #[test]
-    fn the_pane_roll_is_the_relief_width_unless_a_legacy_key_overrides_it() {
-        set_plate_bevel_width(None);
-        assert_eq!(plate_bevel_width(), crate::layout::bevel_width(), "unset: the relief width");
-        set_plate_bevel_width(Some(12.0));
-        assert_eq!(plate_bevel_width(), 12.0, "the legacy key still wins while a config carries it");
-        set_plate_bevel_width(None);
-        assert_eq!(plate_bevel_width(), crate::layout::bevel_width(), "cleared: back to the relief width");
-    }
-
-    /// The four flat frost keys and the `backdrop_compression` spelling
-    /// inside a `frost` child are reported by path; the block itself and a
-    /// material's `compression` are not.
+    fn the_pane_roll_is_the_relief_width() {
+        let _lock = test_color_state_lock();
+        crate::layout::lazy_init_style_registry();
+        let _ = plate_blur();
+        reload_colors("style {\n surface {\n plate bevel_width=(f64)12.0\n }\n}\n");
+        assert_eq!(plate_bevel_width(), crate::layout::bevel_width(), "a retired key moves nothing");
+        assert_eq!(
+            retired_surface_keys(&crate::config::parse_kdl_to_json("style {\n surface {\n plate bevel_width=(f64)12.0\n }\n}\n")),
+            vec!["style.surface.plate.bevel_width"]
+        );
+        reload_colors("");
+    }
+
+    /// The four flat frost keys, the `backdrop_compression` spelling inside
+    /// a `frost` child and `plate.bevel_width` are reported by path; the
+    /// block itself and a material's `compression` are not.
     #[test]
-    fn retired_frost_keys_are_named_by_path_and_the_block_is_not() {
+    fn retired_surface_keys_are_named_by_path_and_the_block_is_not() {
         let clean: serde_json::Value = serde_json::json!({ "style": { "surface": {
             "plate": { "frost": { "radius": 5.5, "compression": 0.0, "refraction": 0.0 }, "color": "#6c6c7bf2" },
             "material": { "glass": { "frost": { "compression": 0.6 } } }
         } } });
-        assert!(retired_frost_keys(&clean).is_empty());
+        assert!(retired_surface_keys(&clean).is_empty());
         let old: serde_json::Value = serde_json::json!({ "style": { "surface": {
             "plate": { "blur": true, "radius": 1.5, "backdrop_compression": 0.85, "refraction": 0.3,
-                       "frost": { "backdrop_compression": 0.2 } },
+                       "bevel_width": 12.0, "frost": { "backdrop_compression": 0.2 } },
             "material": { "glass": { "frost": { "backdrop_compression": 0.6 } } }
         } } });
-        assert_eq!(retired_frost_keys(&old), vec![
+        assert_eq!(retired_surface_keys(&old), vec![
             "style.surface.plate.blur",
             "style.surface.plate.radius",
             "style.surface.plate.backdrop_compression",
             "style.surface.plate.refraction",
+            "style.surface.plate.bevel_width",
             "style.surface.plate.frost.backdrop_compression",
             "style.surface.material.glass.frost.backdrop_compression",
         ]);
-        assert!(retired_frost_keys(&serde_json::json!({})).is_empty());
+        assert!(retired_surface_keys(&serde_json::json!({})).is_empty());
     }
 
     #[test]
diff --git a/src/scene/material.rs b/src/scene/material.rs
index d4fb58c..1604e26 100644
--- a/src/scene/material.rs
+++ b/src/scene/material.rs
@@ -628,7 +628,7 @@ mod tests {
         style {
             surface {
                 param color=(rgba)"#05050840"
-                plate bevel_width=(f64)12.0 {
+                plate {
                     frost compression=(f64)0.6 refraction=(f64)0.3
                     root corner_radius=(i64)24
                 }
@@ -646,7 +646,7 @@ mod tests {
                         frost compression=(f64)0.6 refraction=(f64)0.3
                     }
                 }
-                plate material="glass" bevel_width=(f64)12.0 {
+                plate material="glass" {
                     root corner_radius=(i64)24
                 }
                 relief depth=(f64)0.08
@@ -700,7 +700,7 @@ mod tests {
     /// (bool)false` is not. The four scattered keys it replaced (`blur`,
     /// `radius`, `backdrop_compression`, `refraction`) are RETIRED, not
     /// aliases: a config carrying one is reported by path
-    /// (`color::retired_frost_keys`) and the key does nothing — `blur=true`
+    /// (`color::retired_surface_keys`) and the key does nothing — `blur=true`
     /// alone is sharp, a flat `radius` moves nothing, and the old knob name
     /// inside the block is ignored too.
     #[test]
@@ -713,7 +713,7 @@ mod tests {
             crate::color::reload_colors(&doc(plate));
             (crate::color::plate_blur(), Frost::from_style())
         };
-        let retired = |plate: &str| crate::color::retired_frost_keys(&crate::config::parse_kdl_to_json(&doc(plate)));
+        let retired = |plate: &str| crate::color::retired_surface_keys(&crate::config::parse_kdl_to_json(&doc(plate)));
         let frosted = |c: f32, r: f32, rad: f32| Frost::Frosted { compression: c, refraction: r, radius: rad };
         assert_eq!(load("frost radius=(f64)3.0 compression=(f64)0.4 refraction=(f64)0.1"), (true, frosted(0.4, 0.1, 3.0)));
         assert!(retired("frost radius=(f64)3.0 compression=(f64)0.4 refraction=(f64)0.1").is_empty());