feat(02-03): meta.json — urls[] + schemaVersion (D-P2-02 + D-P2-03; replaces url:string)

- src/shared/types.ts SessionMetadata: REPLACE `url: string` with
  `urls: string[]`; ADD `schemaVersion: string` as the first field.
  Total 8 fields. Field-emission order follows source-declaration order
  (TypeScript object-literal insertion order; JSON.stringify emits in
  insertion order per ECMA-262). Docstring cites D-P2-02 + D-P2-03 +
  Plan 02-01 Task 3 planner-resolved 8th field decision + F2 empty-array
  permission.

- src/background/index.ts:
  * Import { initTabUrlTracker, snapshotOpenTabs, getTabUrlsSeen } from
    './tab-url-tracker'.
  * Register initTabUrlTracker() at module top-level alongside
    chrome.downloads.onChanged (Plan 02-02 precedent for D-P2-* feature
    registration). Defensive try/catch matches the surrounding chrome.*
    listener pattern; tracker module has its own initialized flag for
    idempotency.
  * createArchive: snapshotOpenTabs() before reading getTabUrlsSeen()
    (DEC-011 Amendment 1 capability — captures tabs opened but never
    activated). Empty urls[] emitted faithfully per F2 (no fake
    extension-origin sentinel; logger.warn for diagnostic visibility on
    whole-desktop-no-tab sessions).
  * metadata literal: schemaVersion: '2' first, urls (not url), 8 fields
    total. ECMA-262 insertion-order guarantee + JSON.stringify deliver
    the canonical wire shape.

- Always-on charter preserved: createArchive does NOT call
  clearTabUrlsSeen() — tracker continues accumulating across saves
  (Plan 01-09 Amendment 3 invariant).

Verification:
- npx tsc --noEmit → clean.
- npm run build → clean (dist/assets/index.ts-8LkXuqac.js 378.82 kB,
  ~+2 kB vs pre-Task-2 baseline for the new tab-url-tracker module).
- npx vitest run → 171/171 GREEN (was 163 GREEN / 8 RED; +8 GREEN net).
- Tier-1 grep gate: 13/13 GREEN unchanged.

Closes 8 RED tests:
- tests/background/meta-json-urls-schema.test.ts Tests 1+2 (Tests 3+4+5
  flipped in Task 1).
- tests/build/strict-meta-json-validation.test.ts Tests 1+3+8 (Tests 2,
  4, 5, 6, 7 remain GREEN regression guards).

src/shared/types.ts

@@ -130,10 +130,36 @@ export interface UserEvent {
   meta?: Record<string, unknown>;
 }
 
-// Метаданные сессии
+// Метаданные сессии.
+//
+// Phase 2 Plan 02-03 — D-P2-02 + D-P2-03 schema-breaking amendment
+// (2026-05-20; closes audit P1 #10):
+//
+//   - `url: string` REPLACED by `urls: string[]`. Captures the operator's
+//     multi-tab context during the rolling 30 s recording window — not
+//     just the active-at-save tab. Fed by the new
+//     `src/background/tab-url-tracker.ts` module via chrome.tabs.onActivated
+//     + chrome.tabs.onUpdated listeners + a SAVE-time
+//     chrome.tabs.query({}) snapshot (DEC-011 Amendment 1 grants the
+//     `tabs` permission). Empty array IS permitted (F2 — whole-desktop-
+//     no-tab session).
+//
+//   - `schemaVersion: string` ADDED as the 8th field. Value '2' marks the
+//     D-P2-02 url→urls cutover; future schema bumps increment. The 8th
+//     field name was planner-suggested in Plan 02-01 Task 3 and ratified
+//     here as the lockstep for tests/build/strict-meta-json-validation.test.ts
+//     EXPECTED_KEYS.
+//
+// Total field count: 8 (per D-P2-03 strict exact-shape rule).
+//
+// Field-emission order follows source-declaration order: TypeScript object
+// literals preserve insertion order, and JSON.stringify emits in insertion
+// order per ECMA-262 §9.1.11.1 — so the meta.json output mirrors this
+// interface line-by-line.
 export interface SessionMetadata {
+  schemaVersion: string;
   timestamp: string;
-  url: string;
+  urls: string[];
   userAgent: string;
   extensionVersion: string;
   videoBufferSeconds: number;