Deepen SAMS match loading and harden SSR cache-peek paths

[terijaki]

Summary

• Deepen SAMS modules: extract match loading into sams-match-loader.server.ts, move teams sync into lib/sams, and remove undeployed read Lambdas.
• Harden SSR: cache-peek loaders with season fallback, resilient Promise.allSettled on public routes, and effective-input fallback when DynamoDB/cache peek fails.
• Align client staleTime with the 5‑minute match cache TTL; clarify season disagreement (majority / most-recent) in ADR + CONTEXT.md.
• Add unit coverage for SSR/effective-input paths and empty-tolerant Playwright smokes (DynamoDB-dependent cases skip without AWS_REGION).

Test plan

• vp check and vp test pass
• bun run test:e2e e2e/sams-smoke.spec.ts — homepage + /termine pass without AWS; DynamoDB cases skip unless AWS_REGION / WEBAPP_URL against vpr server
• Manually: /termine, /tabelle, /teams/$slug load without calling getSamsMatchesFn in loaders; empty SAMS sync still renders page shells
• With synced clubs/teams: season-scoped cache/API path includes for-season on cache miss