feat(themes): #53 last previews + quarantine neon-glass broken bar

Capture executive-slate + neon-glass preview.png (480x270, theme-shot) —
all 24 themes now have picker previews. Quarantine neon-glass's broken
whole-swap: its waybar.css referenced @accent/@base/… with no
@define-color block, and waybar.nix reads a whole-swap css raw (no palette
prepend), so applying it rendered broken bar colours. Removing it falls
back to the generated bar from the theme's JSON palette.

Verified: V2 theme-shot renders viewed — executive-slate clean; neon-glass
bar now renders correctly, no config-error banner. V0 flake check green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agent/JOURNAL.md

@@ -17,6 +17,22 @@ Template:
 
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+## 2026-07-09 — #53 theme previews + neon-glass quarantine
+- **Task:** NEXT #53 — capture the last two missing previews + resolve the
+  neon-glass broken whole-swap. Product call: **quarantine**.
+- **Did:** Confirmed the contract (working whole-swaps carry 12–23
+  `@define-color` blocks; `waybar.nix:448` reads the whole-swap css **raw**,
+  no palette prepend — so neon-glass's 0-`@define-color` css is genuinely
+  broken). `git rm themes/neon-glass/waybar.css` → falls back to the generated
+  bar from its (fine) JSON palette. Rendered executive-slate + neon-glass via
+  theme-shot; captured 480×270 `preview.png` for both — **all 24 themes now
+  have previews**.
+- **Verified:** **V2** — viewed both renders: executive-slate clean; neon-glass
+  bar now renders correctly (generated palette), no banner. V0 flake check green
+  with the css removed.
+- **Pending:** none. Optional: hand `btop.theme` for the 3 identity themes; a
+  hardware recapture to match the floating-terminal composition (nicety note).
+
 ## 2026-07-09 — #54 installer safety + polish (delegated, worktree)
 - **Task:** NEXT #54. Sonnet worktree agent (installer only).
 - **Did:** offline `compose-lock` failure fail-closes (reuses the