v2 Phase 1: ingestion + SQLite foundation

- Persistence via Node's built-in node:sqlite (zero native deps) on a Docker
  volume: response cache, source health, fixture↔provider id map, per-fixture
  enrichment, ingest log. Runtime bumped to node:24-slim + --experimental-sqlite.
- Resilient fetcher: DB cache + per-source rate-limit + jittered backoff +
  circuit-breaker (blocked sources trip + skip; UI reads DB, never breaks).
- ESPN hidden API as the PRIMARY rich source (works from the VPS where SofaScore
  403s): scoreboard (live scores w/ clock) + summary (venue, H2H, recent form,
  lineups, team stats). football-data / SofaScore are fallbacks.
- Scheduler: maps all 72 group fixtures to ESPN event ids, polls live on a
  dynamic cadence, enriches imminent fixtures into match_ext. /api/sources/health.
- Verified: DB populates (real H2H + form for opening matches), 22 tests pass,
  Docker image runs node:sqlite on the volume and persists across restart.

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

server/src/tournament.ts

@@ -68,6 +68,16 @@ export class TournamentState {
     return this.fixtures;
   }
 
+  /** Which fixture number does a (home, away) pairing map to? Used by the
+   *  ingestion layer to key provider event ids against our fixtures. */
+  matchFixtureNum(home: string, away: string, stage: Fixture['stage'] = 'group', kickoff: string | null = null): number | null {
+    const f = this.findFixture({
+      home, away, group: null, stage, kickoff,
+      homeScore: null, awayScore: null, status: 'scheduled', minute: null,
+    });
+    return f?.num ?? null;
+  }
+
   /** True if any match is live or kicks off within `windowMs` of now — used to
    *  poll the APIs often during match windows and rarely when nothing is on. */
   hasLiveActivity(windowMs: number): boolean {