feat(themes): community Theme Store + semantic-token refactor (#1009)

* feat(themes): add semantic tokens for the theme-store contract (B0 P1)

Additive: define --highlight, --accent-2, --bg-deep, --bg-elevated and
--text-on-accent on the :root base as --ctp-* mappings. They resolve
per-theme automatically and nothing consumes them yet (zero behaviour
change) — groundwork for replacing direct --ctp-* use in components.

* refactor(themes): components consume semantic tokens, not --ctp-* (B0 P2)

Replace every direct --ctp-* reference in component/layout/track CSS and
TSX inline styles with the readable semantic token (--bg-app, --accent,
--highlight, --text-on-accent, …). --ctp-* now survives only as the
Catppuccin palette layer the base maps from, and as the deliberate
categorical rainbow in Composers/Genres/artistsHelpers (left untouched).

This is the readable contract surface for the community theme store.
Divergences (theme set a semantic var != its --ctp- source) are
corrections — the element now uses the theme's real semantic colour.

* feat(themes): add player-bar title/artist color tokens

New optional --player-title / --player-artist, defaulting to --text-primary / --text-secondary so nothing changes unless a theme overrides them. Lets a theme give the now-playing readout its own colour as a plain token.

* refactor(themes): token-only theme library (flatten, whitelist, one file per theme)

Turn every built-in theme into a single self-contained [data-theme] var block of semantic whitelist tokens (plus the internal --ctp-* palette layer):

- Flatten all themes: drop structural override rules, @keyframes, and global-token overrides (radius / shadow-elevation / transition / spacing / font / focus-ring). Signature player-bar readout colours are preserved via the new --player-title / --player-artist tokens.

- Normalize the var blocks to the semantic whitelist: drop the alternate token vocabulary (nav-active / scrollbar / bg-input / success / border-default / ...); rename --success -> --positive and --border-default -> --border where no whitelist equivalent was set. Migrate the few components that read those tokens to the whitelist equivalents.

- Split multi-theme files so each theme ships as its own file, making the built-in set 1:1 with the per-theme store packaging.

Kept as-is (built-in, not flattened): the two colour-blind-safe accessibility themes, plus the two curated core skins.

* chore(themes): remove seven themes retired after the token refactor

These themes leaned on heavy structural overrides and were dropped rather than flattened. Full removal each: the CSS file(s), the index.css import, the Theme type union, and the ThemePicker entry.

* feat(themes): granular tokens — track lists

Wire track rows to per-region tokens: row hover (--row-hover), the now-playing
row + indicator (--row-playing-bg / --row-playing-text), track title/artist/
number/duration text, column-header text, row dividers, and the resize-handle
active colour. Covers the desktop tracklist, the shared song-row (Tracks hub /
search), and the mobile tracklist. Drop a baked border fallback. Visual no-op.

* feat(themes): granular tokens — cards

Wire album and artist cards to per-region tokens (--card-hover-border,
--card-title, --card-subtitle, --card-placeholder-bg). Visual no-op.

* fix(themes): drop undefined/baked colour aliases

Replace the undefined --bg-surface (resolved to nothing — broken placeholder
backgrounds and filter input) with --card-placeholder-bg / --input-bg, and the
baked-hex aliases --color-error / --color-warning with --danger / --warning so
themes can actually recolour them.

* feat(themes): Spectrum demo theme + trim unused cascade tokens

Add a loud built-in demo theme that gives each region its own hue (sidebar
green, player pink, lists cyan, cards gold, menus red, controls blue) so the
per-region granularity is obvious when you switch to it. Drop two unused
cascade tokens (--sidebar-text-active, --row-active-bg) and the unused
on-media block (those media surfaces stay static by design).

* style(themes): make Spectrum demo brutally loud

Full-saturation neon per region (toxic green sidebar, magenta player, cyan
lists, acid-yellow cards, blood-red menus, electric-blue controls, purple
scrollbar) so the per-region separation is unmistakable. The earlier soft
tints were too subtle to read.

* feat(themes): name the granular demo theme Braindead

* feat(themes): granular per-region tokens — cascade layer + sidebar

Add an optional per-region token layer (semantic-cascade.css) so a theme can
recolour individual regions — sidebar hover, player controls, list rows,
menus, inputs, on-media surfaces — independently of the global tokens. Every
token defaults to its base token (or a media-safe literal), so this is a
visual no-op until a theme overrides one; it only adds control points.

Wire the sidebar region as the first consumer and drop the baked grey
fallbacks (--bg-tertiary, etc.) that no theme could reach.

* feat(themes): granular tokens — controls, menus, scrollbar

Wire inputs, buttons, sliders, the custom-select, context menus, submenus and
modals to per-region tokens, and tokenise the scrollbar. Complete B0 by
dropping the last direct --ctp-* references in the input/button/progress/
scrollbar utility CSS.

Fix three undefined-token bugs that fell back to nothing (so no theme could
reach them): --surface-2 (context-menu hover had no highlight), --bg-surface
(submenu create-input had no background), and the baked grey fallbacks in the
custom-select. Every other new token defaults to today's value — a visual
no-op that only adds override points.

* feat(themes): granular tokens — player bar

Wire the desktop player bar's transport controls, time toggle, and overflow
menu to per-region tokens (--player-control, --player-time-toggle-*, etc.).
Fix the undefined --surface-hover/--surface-active grey fallbacks on the time
toggle. Visual no-op; defaults match today's values.

* chore(themes): remove empty theme stub files

Six theme CSS files were reduced to comment-only stubs by the flatten
sweep but their files and @import lines remained. Five are empty
structural companions of now-flattened themes (morpheus, p-dvd,
aero-glass, luna-teal) and two are orphans of cut themes
(order-of-the-phoenix, pandora). Removed the files and their imports.

* feat(themes): runtime injection foundation for the theme store

Plumbing for installed community themes ahead of the in-app store UI,
nothing user-visible yet:

- installedThemesStore: persisted (localStorage) record of installed
  community themes incl. their CSS text, so an active community theme is
  available synchronously at startup (no flash, fully offline).
- themeInjection: reconcile <head> <style data-installed-theme> elements
  with the store; lightweight defense-in-depth sanitize on top of CI.
- themeRegistry: jsDelivr registry client with a 12h localStorage cache
  and stale-on-error fallback.
- App: inject installed themes before applying data-theme, in both webviews.
- themeStore: widen the Theme type to accept dynamic installed ids.

* feat(themes): dedicated Themes settings tab

Move theme selection and the day/night scheduler out of Appearance into
a new dedicated Themes tab — the future home of the community Theme Store.
Appearance keeps grid columns, visual options, UI scale, font and seekbar.

- ThemesTab: theme picker + scheduler (relocated verbatim).
- AppearanceTab: drop the two relocated sections + now-unused imports.
- Register the tab in settingsTabs (Tab union, resolveTab, search index)
  and Settings (tab bar, render, label map).
- i18n: settings.tabThemes in all 9 locales.

* feat(themes): community Theme Store browse + install

Add the Theme Store section to the Themes tab:

- Fetch the jsDelivr registry (12h cache, stale-on-error fallback).
- Search by name/author/description + filter by light/dark + refresh.
- Per-row CDN thumbnail, name, author, description and actions:
  Install / Apply / Update / Uninstall. Installing fetches the CSS,
  persists it (localStorage) and the runtime injection applies it;
  uninstalling the active theme falls back to the matching core.
- Rating slot left reserved (deferred).
- i18n: themeStore* keys in all 9 locales.

* feat(themes): slim bundle to fixed cores + flat Themes tab

Remove the 86 store palettes (incl. braindead) from the app bundle — the
CSS files, their index.css imports, the Theme union and the picker data —
leaving only the six fixed cores (Catppuccin Mocha/Latte, Kanagawa Wave,
Stark HUD, Vision Dark/Navy). Everything else installs from the store.

Themes tab is rebuilt flat (no collapsible accordions):
- "Your Themes": one card grid of the fixed cores + installed community
  themes; click to apply, uninstall on community ones (active theme falls
  back to the matching core). Catppuccin prefix on Mocha/Latte; a CVD-safe
  pill on the colour-blind-safe Vision themes.
- Scheduler day/night options include installed themes.
- Theme Store: alphabetical order, thumbnail lightbox, and a submit hint
  above the search linking to the themes repository.
- Nav order: Servers, Library, Audio, Themes, Appearance, Lyrics, …
- ThemePicker accordion removed; fixed-theme data moved to fixedThemes.ts.
- i18n for all new strings across 9 locales.

* feat(themes): reset removed-from-bundle themes to a bundled fallback

After slimming the bundle to the six fixed core themes, a profile upgraded
from an older build may have an active or scheduler theme that is now
store-only and not installed — it has no [data-theme] block and would render
as unstyled :root. Reset any theme/themeDay/themeNight that is neither bundled
nor installed to a bundled fallback: Mocha for the main + night slots, Latte
for the day slot. Runs synchronously in runPreReactBootstrap, rewriting the
persisted selection in localStorage before React mounts (no flash; Zustand
rehydrates after first paint). No auto-install and no network — the fallback
is always a bundled theme, so it works offline.

* feat(themes): floating back-to-top button on the Themes tab

The Themes tab can get long (theme grid + scheduler + full store list), so
add a floating back-to-top affordance that appears once the page is scrolled
and smooth-scrolls to the top. It is portalled into the route host and
positioned absolute against it — the main scroll viewport sets contain: paint,
which would otherwise make position: fixed resolve against the scrolling box
and drift with the content. Reusable component (scroll viewport id + threshold
props); i18n common.backToTop added in all nine locales.

* feat(themes): accessibility + state polish for the Theme Store

- Reuse the shared CoverLightbox for the thumbnail preview instead of a
  second inline dialog — gains a visible close button and a focus-managed,
  portalled dialog, and drops duplicated markup.
- Theme cards expose aria-pressed so assistive tech announces the selected
  theme, not just the visual check.
- Transient store messages get live-region roles (loading/empty/install
  failure = status, fetch error = alert).
- Thumbnails degrade gracefully when offline/missing (hide the broken-image
  glyph; the thumbnail button no longer stretches with the row, so its
  background can't show as letterbox bars).

* feat(themes): larger store-row thumbnails (120x75 -> 200x125)

The list previews were too small to make a theme out; bump the display size
(same 1.6 aspect). Thumbnails are now served at 720x450, so the larger
display stays crisp.

* fix(themes): bust thumbnail cache on registry change

jsDelivr serves theme thumbnails with a 7-day max-age, so when a thumbnail
is updated the webview keeps showing its cached old image (the path is
unchanged). Append the registry's generatedAt as a cache-busting query to
the thumbnail URLs (list + lightbox); it changes on every themes push, so a
registry refresh makes the webview re-fetch and reflect the current CDN
image instead of a stale one.

* docs(themes): changelog + credits for the Theme Store

Add the 1.48.0 "Themes — community Theme Store" changelog entry (PR #1009)
and the matching line in the Psychotoxical credits.

* fix(themes): address PR review (uninstall hygiene, validation, polish)

Uninstall/scheduler & validation:
- uninstallTheme() repairs every selection slot (active + day + night), not
  just the manual one, and is shared by both uninstall buttons (dedup).
- Validate theme CSS at install time and skip persisting CSS that won't inject
  (no more "installed/active but renders nothing" with no feedback).
- Harden the runtime validator: exactly one rule, scoped exactly to the
  theme's [data-theme='<id>'] selector (no unscoped/foreign selectors), no
  at-rules, url() only data:, no expression()/javascript:, size-capped.

Tokens & polish:
- Fix three dangling undefined tokens (--surface-2 x2, --bg-surface).
- Finish the warning/success token sweep (--warning / --positive, themeable).
- Apply the active theme synchronously before React mounts (no first-frame
  flash) and inject installed themes up front.
- One-time, dismissible notice when the slim-bundle migration reset a theme.
- Update badge uses semver, not string inequality.
- Offline/stale indicator in the store; cross-window theme sync; drop the now
  dead REMOVED_THEME_REMAP and Card.mode field.

Tests: themeInjection (validator + sync), themeRegistry (cache/force/stale/
malformed), uninstallTheme (slot repair), migration notice. i18n in all nine
locales. Full suite green (1755 tests).

* test(bootstrap): cover startup theme apply + cross-window sync

The review fixes added applyThemeAtStartup / installCrossWindowThemeSync to
bootstrap.ts (a hot-path file) without tests, dropping its coverage to 68.3%
and failing the frontend hot-path coverage gate (>=70%). Add unit tests for
both (and the no-op / malformed-storage paths); bootstrap.ts is back to ~98%.

src/components/settings/AppearanceTab.tsx

@@ -1,7 +1,7 @@
 import { useEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { invoke } from '@tauri-apps/api/core';
-import { Clock, LayoutGrid, Palette, Sliders, Type, ZoomIn } from 'lucide-react';
+import { LayoutGrid, Palette, Sliders, Type, ZoomIn } from 'lucide-react';
 import { useAuthStore } from '../../store/authStore';
 import {
   LIBRARY_GRID_MAX_COLUMNS_MAX,
@@ -11,13 +11,11 @@ import type { SeekbarStyle } from '../../store/authStoreTypes';
 import { useFontStore, FontId } from '../../store/fontStore';
 import { useThemeStore } from '../../store/themeStore';
 import { IS_LINUX, IS_WINDOWS } from '../../utils/platform';
-import CustomSelect from '../CustomSelect';
 import SettingsSubSection from '../SettingsSubSection';
-import ThemePicker, { THEME_GROUPS } from '../ThemePicker';
 import { SeekbarPreview } from '../WaveformSeekPreview';
 
 export function AppearanceTab() {
-  const { t, i18n } = useTranslation();
+  const { t } = useTranslation();
   const auth = useAuthStore();
   const theme = useThemeStore();
   const fontStore = useFontStore();
@@ -30,88 +28,6 @@ export function AppearanceTab() {
 
   return (
     <>
-      <SettingsSubSection
-        title={t('settings.theme')}
-        icon={<Palette size={16} />}
-      >
-        <div className="settings-card">
-          {theme.enableThemeScheduler && (
-            <div className="settings-hint settings-hint-info" style={{ marginBottom: '0.75rem' }}>
-              {t('settings.themeSchedulerActiveHint')}
-            </div>
-          )}
-          <ThemePicker value={theme.theme} onChange={v => theme.setTheme(v as any)} />
-        </div>
-      </SettingsSubSection>
-
-      <SettingsSubSection
-        title={t('settings.themeSchedulerTitle')}
-        icon={<Clock size={16} />}
-      >
-        <div className="settings-card">
-          <div className="settings-toggle-row">
-            <div>
-              <div style={{ fontWeight: 500 }}>{t('settings.themeSchedulerEnable')}</div>
-              <div style={{ fontSize: 12, color: 'var(--text-muted)' }}>{t('settings.themeSchedulerEnableSub')}</div>
-            </div>
-            <label className="toggle-switch" aria-label={t('settings.themeSchedulerEnable')}>
-              <input type="checkbox" checked={theme.enableThemeScheduler} onChange={e => theme.setEnableThemeScheduler(e.target.checked)} />
-              <span className="toggle-track" />
-            </label>
-          </div>
-          {theme.enableThemeScheduler && (() => {
-            const themeOptions = THEME_GROUPS.flatMap(g =>
-              g.themes.map(th => ({
-                value: th.id,
-                label: th.family ? `${th.family} ${th.label}` : th.label,
-                group: g.group,
-              }))
-            );
-            const use12h = i18n.language === 'en';
-            const hourOptions = Array.from({ length: 24 }, (_, i) => {
-              const value = String(i).padStart(2, '0');
-              const label = use12h
-                ? `${i % 12 === 0 ? 12 : i % 12} ${i < 12 ? 'AM' : 'PM'}`
-                : value;
-              return { value, label };
-            });
-            const minuteOptions = ['00', '05', '10', '15', '20', '25', '30', '35', '40', '45', '50', '55'].map(m => ({ value: m, label: m }));
-            const dayH = theme.timeDayStart.split(':')[0];
-            const dayM = theme.timeDayStart.split(':')[1];
-            const nightH = theme.timeNightStart.split(':')[0];
-            const nightM = theme.timeNightStart.split(':')[1];
-            return (
-              <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(160px, 1fr))', gap: '1rem', marginTop: '1rem' }}>
-                <div className="form-group">
-                  <label className="settings-label" style={{ marginBottom: 6 }}>{t('settings.themeSchedulerDayTheme')}</label>
-                  <CustomSelect value={theme.themeDay} onChange={theme.setThemeDay} options={themeOptions} />
-                </div>
-                <div className="form-group">
-                  <label className="settings-label" style={{ marginBottom: 6 }}>{t('settings.themeSchedulerDayStart')}</label>
-                  <div style={{ display: 'flex', gap: '6px', alignItems: 'center' }}>
-                    <CustomSelect value={dayH} onChange={v => theme.setTimeDayStart(`${v}:${dayM}`)} options={hourOptions} />
-                    <span style={{ color: 'var(--text-muted)', fontWeight: 600 }}>:</span>
-                    <CustomSelect value={dayM} onChange={v => theme.setTimeDayStart(`${dayH}:${v}`)} options={minuteOptions} />
-                  </div>
-                </div>
-                <div className="form-group">
-                  <label className="settings-label" style={{ marginBottom: 6 }}>{t('settings.themeSchedulerNightTheme')}</label>
-                  <CustomSelect value={theme.themeNight} onChange={theme.setThemeNight} options={themeOptions} />
-                </div>
-                <div className="form-group">
-                  <label className="settings-label" style={{ marginBottom: 6 }}>{t('settings.themeSchedulerNightStart')}</label>
-                  <div style={{ display: 'flex', gap: '6px', alignItems: 'center' }}>
-                    <CustomSelect value={nightH} onChange={v => theme.setTimeNightStart(`${v}:${nightM}`)} options={hourOptions} />
-                    <span style={{ color: 'var(--text-muted)', fontWeight: 600 }}>:</span>
-                    <CustomSelect value={nightM} onChange={v => theme.setTimeNightStart(`${nightH}:${v}`)} options={minuteOptions} />
-                  </div>
-                </div>
-              </div>
-            );
-          })()}
-        </div>
-      </SettingsSubSection>
-
       <SettingsSubSection
         title={t('settings.libraryGridMaxColumnsTitle')}
         icon={<LayoutGrid size={16} />}