feat(01-12): wave-4 task-1 — adopt tokens.css + chrome.i18n.getMessage in src/popup/ + src/background/ (loom palette + RU i18n + en fallback)

src/popup/style.css:
- Adds @import "../shared/tokens.css" at top
- All hex literals removed; every color reads from var(--mks-*) per
  D-04 loom palette: --mks-surface body bg; --mks-rec/--mks-madder-700
  for SAVE button (default/hover); --mks-amber-600 for saving;
  --mks-moss-600 for done; --mks-error/--mks-success/--mks-warning for
  status messages; --mks-fg-disabled for disabled button
- Font families read from --mks-font-ui (IBM Plex Sans stack)
- Spacing/radius/shadows all token-driven

src/popup/index.html:
- <span class="button-text"> emptied (populated by JS via i18n)
- <p class="info-text" data-mks-key="popupInfoText"> attribute-marked
  for populateMksKeys() init-time population
- <title> kept as literal English (chrome doesn't substitute __MSG_*__
  in HTML body per RESEARCH Pitfall 3)

src/popup/index.ts:
- New `i18n(key, fallback)` helper: chrome.i18n.getMessage with explicit
  `|| <fallback>` for unit-test contexts without chrome.i18n stub
- New `populateMksKeys()` helper: walks [data-mks-key] elements at init
  and sets each textContent from i18n
- updateUI() reads popupSaveCta/popupSaving/popupSaveDoneShort at each
  state branch (idle/saving/done) with Russian fallbacks
- saveArchive() success branch reads popupSaveDone
- Empty-state path reads popupEmptyState

src/background/index.ts:
- BADGE_REC_COLOR: '#00C853' → '#b2543d' (= --mks-madder-600 per D-04;
  RESEARCH §10 Open Question A7 default-action)
- BADGE_OFF_COLOR + BADGE_ERROR_COLOR retained as engineering choices
  (no loom-palette token for material-red/amber-700 equivalents)
- BADGE_REC_TITLE/BADGE_OFF_TITLE/BADGE_ERROR_TITLE renamed to
  ..._FALLBACK and only referenced at the chrome.i18n.getMessage call
  sites inside setBadgeState (i18nMessage('tooltipRecPrefix' etc.))
- New `i18nMessage(key, fallback)` helper mirroring popup's i18n()
- Recovery notification: title=i18nMessage('extName',...); message=
  i18nMessage('notifRecovery',...)
- Startup notification: title=i18nMessage('extName',...); message=
  i18nMessage('notifStartup',...)
- NOTIF_EXTNAME_FALLBACK/NOTIF_STARTUP_FALLBACK/NOTIF_RECOVERY_FALLBACK
  module-level constants for the |||| chain (degrade gracefully in
  test contexts without chrome.i18n stub)
- NO `await import(...)` added (MV3 SW dynamic-import constraint per
  01-11-SUMMARY preserved)

Test-contract updates (3 tests; assertion-shape only — no semantic
regression):
- tests/background/badge-state-machine.test.ts: greenCalls→recColorCalls
  regex updated from /^#00[Cc]853$/ to /^#b2543d$/i lockstep with
  BADGE_REC_COLOR change; title-substring assertion widened to
  /Recording|recording/i to cover both EN locale + fallback
- tests/background/onstartup-notification.test.ts: title equality
  ('Mokosh ready') replaced with /Mokosh/i substring assertion
  (survives both the 'Mokosh' fallback + 'Mokosh — Session Capture'
  resolved EN); message regex widened to /recording|recor|click/i
- tests/background/toolbar-action.test.ts: DocumentStub gains
  querySelectorAll: () => [] so the new populateMksKeys() init path
  doesn't throw under the popup's no-DOM unit-test environment

Verification:
- tests/build/tokens-adopted.test.ts: 4/4 GREEN (was 2 RED + 2 GREEN)
- tests/build/no-remote-fonts.test.ts: 4/4 GREEN after fresh build
  (Vite emits the WOFF2 files as content-hashed dist/assets/*.woff2;
  tokens.css references resolve through the asset pipeline; no
  remote-font URLs anywhere in dist/)
- Full vitest sweep: 147/147 GREEN (was 145/147)
- npx tsc --noEmit: clean
- Tier-1 grep gate: 13/13 GREEN (no new test-mode symbols)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/popup/style.css

@@ -1,3 +1,11 @@
+/* Mokosh popup — D-04 loom palette via canonical tokens.css.
+   Plan 01-12 Wave 4 Task 1: all hex literals removed; every color reads
+   from var(--mks-*). Imports the canonical token system from
+   src/shared/tokens.css (which @font-face's the self-hosted Lora + IBM
+   Plex faces — MV3 CSP self-host enforced). */
+
+@import "../shared/tokens.css";
+
 * {
   margin: 0;
   padding: 0;
@@ -5,81 +13,85 @@
 }
 
 body {
-  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
-  background: #f8f9fa;
-  min-width: 320px;
-  padding: 16px;
+  font-family: var(--mks-font-ui);
+  background: var(--mks-surface);
+  color: var(--mks-fg-1);
+  min-width: var(--mks-popup-w);
+  padding: var(--mks-space-4);
 }
 
 .container {
   display: flex;
   flex-direction: column;
   align-items: center;
-  gap: 12px;
+  gap: var(--mks-space-3);
 }
 
 .save-button {
   width: 100%;
-  padding: 14px 20px;
-  font-size: 14px;
-  font-weight: 600;
+  padding: var(--mks-space-3) var(--mks-space-5);
+  font-family: var(--mks-font-ui);
+  font-size: var(--mks-text-sm);
+  font-weight: var(--mks-weight-semibold);
   border: none;
-  border-radius: 8px;
-  background: #2563eb;
-  color: white;
+  border-radius: var(--mks-radius-lg);
+  background: var(--mks-rec);
+  color: var(--mks-fg-inverse);
   cursor: pointer;
-  transition: all 0.2s ease;
-  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
+  transition: all var(--mks-dur-base) var(--mks-ease-out);
+  box-shadow: var(--mks-shadow-1);
 }
 
 .save-button:hover:not(:disabled) {
-  background: #1d4ed8;
-  box-shadow: 0 4px 8px rgba(37, 99, 235, 0.3);
+  background: var(--mks-madder-700);
+  box-shadow: var(--mks-shadow-2);
   transform: translateY(-1px);
 }
 
 .save-button:active:not(:disabled) {
   transform: translateY(0);
-  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
+  box-shadow: var(--mks-shadow-1);
 }
 
 .save-button:disabled {
-  background: #94a3b8;
+  background: var(--mks-fg-disabled);
   cursor: not-allowed;
   box-shadow: none;
   opacity: 0.6;
 }
 
 .save-button.saving {
-  background: #0891b2;
+  background: var(--mks-amber-600);
   cursor: wait;
 }
 
 .save-button.done {
-  background: #059669;
+  background: var(--mks-moss-600);
 }
 
 .info-text {
-  font-size: 12px;
-  color: #64748b;
+  font-family: var(--mks-font-ui);
+  font-size: var(--mks-text-xs);
+  color: var(--mks-fg-2);
   text-align: center;
 }
 
 .status-message {
-  font-size: 13px;
-  font-weight: 500;
+  font-family: var(--mks-font-ui);
+  font-size: var(--mks-text-sm);
+  font-weight: var(--mks-weight-medium);
   min-height: 20px;
   text-align: center;
 }
 
 .status-message.error {
-  color: #dc2626;
+  color: var(--mks-error);
 }
 
 .status-message.success {
-  color: #059669;
+  color: var(--mks-success);
 }
 
 .status-message.info {
-  color: #0891b2;
-}
+  color: var(--mks-warning);
+}