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>

src/lib/types.ts

@@ -63,7 +63,7 @@ export interface Snapshot {
   /** When the live layer last refreshed (ISO), or null if seed-only. */
   updatedAt: string | null;
   /** Which live source produced the current scores. */
-  source: 'seed' | 'football-data' | 'sofascore';
+  source: 'seed' | 'espn' | 'football-data' | 'sofascore';
   fixtures: Fixture[];
   /** Group letter → ranked standings. */
   tables: Record<string, StandingRow[]>;