feat: state platform metrics and chrome in theme

docs/CHECKLIST.md

@@ -9,18 +9,20 @@ is the first downstream consumer; its screens drive the order.
 
 ## Next
 
+- [ ] **Platform metric adoption** — update components one at a time
+      through the review gate against the landed theme tokens. The stated
+      metrics and the radius ladder already flow through the size table,
+      so each stop covers border + focus chrome (`Theme::borders`), the
+      spacing unit (`Theme::spacing`), and the component's stated dims:
+      button (the API template) first, then input, select, menu, popover,
+      dialog, toast, tooltip, alert, combobox, command palette, switch;
+      per-platform targets in
+      [platform-metrics-audit.md](platform-metrics-audit.md).
+
 ## Queue — to follow
 
 Gaps surfaced by the signed comparison; ordered by signed's usage.
 
-- [ ] **Platform metric fidelity** — native-sizing pass over the theme and
-      components: stated `control_height` per platform (macOS 24 measured /
-      Windows 32 / GNOME ≈34 / KDE ≈33), Linux root font sizes (GNOME 14.67px,
-      KDE 13.33px), platform overlay/sm radii, per-source border + focus
-      policy (macOS/GNOME borderless fills, Windows/KDE 1px), titlebar
-      heights (GNOME 47), a theme spacing scale, switch/icon calibration;
-      ranked findings in
-      [platform-metrics-audit.md](platform-metrics-audit.md).
 - [ ] **Virtual list** — generic virtualized variable-height rows with a
       scroll handle, promoted from the editor views' pattern over gpui's
       `list`; signed's PR lists and commit diff drive it.
@@ -55,6 +57,13 @@ Gaps surfaced by the signed comparison; ordered by signed's usage.
 - [x] Platform sources — macOS (NSColor), Windows 11 (UISettings), GNOME
       (portal), KDE (kdeglobals), Omarchy (colors.toml), neutral fallback;
       live watchers for each
+- [x] Platform metric fidelity — stated control/input/menu-row/switch
+      metrics and the full radius ladder per platform, Linux root fonts
+      (GNOME gsettings `font-name`, KDE `kdeglobals font=`), per-source
+      border + focus chrome (`Theme::borders`), and a per-platform spacing
+      unit (`Theme::spacing`); findings in
+      [platform-metrics-audit.md](platform-metrics-audit.md). Components
+      adopt the tokens one by one (see Next)
 
 ### icons (`crates/icons`)
 

docs/platform-metrics-audit.md

@@ -229,6 +229,10 @@ density is frozen at a macOS-ish tuning.
 
 ## Recommended changes, in priority order
 
+Landed 2026-11 with two deviations: Omarchy is grouped with GNOME (it
+styles its apps with adwaita), and macOS's titlebar is stated at the
+measured 32pt rather than queried at runtime (28pt on older builds).
+
 1. **State `control_height` per platform** — add `control_height:
    Option<Pixels>` beside `input_height` on `SystemTheme`, reuse the
    ratio-scaling pattern: macOS 24 (measured), Windows 32, GNOME ≈34, KDE
@@ -248,9 +252,11 @@ density is frozen at a macOS-ish tuning.
    queried rather than a drifted floor (32 on current builds, 28 older);
    Windows stays stated.
 6. **Add a minimal spacing scale to `Theme`** driven by a per-platform base
-   unit (GNOME 6, KDE 4/6/8, others 4); route menu/popover paddings, menu
-   item min-height (GNOME 32), and the hardcoded `min_w_`/`max_w` values
-   through it.
+   unit (GNOME 6, KDE 4/6/8, others 4); route menu/popover paddings and menu
+   row min-heights through it — GNOME 32 (published), Windows ≈33 (padding
+   4/5 + a 20px Body line + 2px item margins), KDE ≈29 (max(font, 20px
+   floors) + 1 + 2×4); the hardcoded `min_w_`/`max_w` surface values stay
+   put — they are platform-invariant.
 7. **Calibrate switches and icons per platform** — macOS 54×24, Windows
    40×20 with 12px knob, KDE 36×18; icon 16 on macOS/Windows.