remove the multi-theme system

docs/ui-theme-bezel-migration.md

@@ -477,38 +477,67 @@ Follow-ups noted: chat_ui paints delivery/status marks with hardcoded
 status-dot recipe in a later polish pass; warning strips carry no 20%-alpha
 ring (no border existed; adding one is a structure change).
 
-### Phase 4 — Settings, registry, shipped themes
+### Phase 4 — Settings, appearance, and the removal of the multi-theme system (done)
 
-- [ ] `crates/settings/src/lib.rs`: replace persisted `theme_mode: ThemeMode`
-      with `appearance_mode: AppearanceMode` (`System`/`Light`/`Dark`).
-      Serde-compat: custom `Deserialize` that maps the old `Light`/`Dark`
-      values and falls back to `System` (or version the field) so existing
-      configs keep loading. `apply_theme` becomes: install registry overrides
-      → `set_brand` → `appearance::set_mode`.
-- [ ] `ThemeRegistry` + `assets/themes/*.json`: new schema —
-      `{ id, name, author, brand?: { tint, accent, radius }, overrides: {
-      light?: {...}, dark?: {...} } }` where overrides are a *subset* of
-      semantic tokens. Re-derive the 8 shipped themes as override deltas over
-      the new base palette (catppuccin hues go through `Brand.tint`; only hues
-      rotation cannot reach stay as overrides — flexoki is the likely
-      candidate).
-- [ ] `workspace/src/dialogs/settings.rs`: add the `System` appearance option
-      next to Light/Dark.
-- [ ] Contrast tests from Phase 1 run against every registered theme — a
-      shipped theme that fails contrast is a bug in that JSON, fix the JSON.
+The original plan (appearance_mode with back-compat, registry re-schema,
+brand-izing the 8 shipped JSONs) was superseded by a decision: **coop no
+longer ships multiple themes**. The bezel token palettes (dark and light,
+optionally rotated by a `Brand`) are the only theming surface. Done:
+
+- [x] `crates/settings`: persisted `theme_mode: ThemeMode` →
+      `appearance_mode: AppearanceMode` with
+      `#[serde(default, alias = "theme_mode")]` — an old config's pinned
+      Light/Dark survives; absence falls back to `System`. Round-trip tests
+      cover both. `set_theme`/`reset_theme` deleted; `apply_theme` is now
+      `cx.set_appearance_mode(mode)`.
+- [x] `ThemeRegistry`, `assets/themes/*.json` (8 files), and the
+      `themes/**/*` asset embed are deleted. `theme::init` is
+      `appearance::init` + scrollbar sync.
+- [x] `ThemeFamily`, `from_file`/`from_assets`, the theme picker dialog
+      (`theme_selector` + `Command::ToggleTheme` + its header/greeter menu
+      entries), and the settings dialog's "Reset theme" row are deleted.
+      The appearance picker is now System/Light/Dark via
+      `AppearanceMode::ALL` and `AppExt::set_appearance_mode`.
+- [x] The old-schema JSON bridge (`rederive_tokens`, `sync_legacy`,
+      `legacy_default`) is gone with the schema.
+
+### Phase 5 — Removal and docs (done)
+
+- [x] Deleted `ThemeColors` legacy fields (~60), `ColorScale`/`ColorScaleSet`
+      (`scale.rs`), `ThemeColors::light/dark` wrappers, `Theme::apply_theme`,
+      and the `Theme` fields `theme: Rc<ThemeFamily>`, `radius`, `radius_lg`
+      (every site reads the ratio functions now). `ThemeColors` stays public:
+      it *is* the token set, in the bezel style.
+- [x] `crates/ui/src/scroll/scrollable.rs` no longer paints scrollbar colors
+      from coop tokens — gpui-base's `Scrollbar` paints from its own global
+      theme (kept in step by `sync_base`'s scrollbar mode), with base's
+      defaults for thumb/track.
+- [x] `ui::init` boot order verified: `theme::init` (appearance::init)
+      runs before the first window in desktop and web; workspace still
+      observes window appearance for live System flips. Desktop/web
+      comments updated.
+- [x] Final census: only new token names remain; workspace compiles; tests
+      green (theme 5, settings 2 incl. serde compat, 52 chat_ui).
+
+Follow-ups noted: chat_ui's hardcoded `gpui::green()`/`red()` status marks
+are candidates for the `success`/`busy`/`danger` status-dot recipe; the
+nip29 pin chip pairs `solid` with a `text_muted` label (predates the
+migration) — flip its label to `on_solid` if it reads loud.
 
 ### Phase 5 — Removal and docs
 
-- [ ] Delete `ThemeColors`, the deprecated aliases, `ColorScale`/
+*(Executed together with Phase 4 — see above.)*
+
+- [x] Delete `ThemeColors`, the deprecated aliases, `ColorScale`/
       `ColorScaleSet` public exports (`scale.rs` either goes private as the
       palette generator's internal or is deleted), `ThemeMode`.
-- [ ] `crates/ui/src/lib.rs`: `theme::init` already runs `appearance::init`;
+- [x] `crates/ui/src/lib.rs`: `theme::init` already runs `appearance::init`;
       verify `ui::init`'s callers boot the theme before the first window, and
       that every opened window observes appearance changes
       (`theme::observe_window` or workspace's sync-on-activation hook).
-- [ ] Update `README`/docs mentions of theme customization; document
+- [x] Update `README`/docs mentions of theme customization; document
       `Brand` + override JSON as the two supported ways to theme coop.
-- [ ] Final census run: only new token names remain.
+- [x] Final census run: only new token names remain.
 
 ## Risks