Repair Farcaster admission alerts and smooth Mini App zoom

[ael-dev3]

What changed

• accept Farcaster's current additive failedTokens notification response while preserving strict validation of known outcomes
• add rollback-safe, token-free operator delivery diagnostics behind the dedicated notification credential
• keep retry state private and out of the version-1 Durable Object record
• slow and spike-compress pinch zoom only inside the Farcaster Mini App; desktop and regular browser behavior remain unchanged

Why

Farcaster added optional per-token failure metadata in April 2026. Warpkeep's exact response parser treated that additive field—even failedTokens: []—as an invalid response, leaving successful admission alerts in the retry queue. Mini App pinch input was also too sensitive in mobile WebViews.

Validation

• auth bridge: 298 unit tests
• Worker runtime: 11 tests
• frontend full suite: completed with two workers
• focused realm gesture suite: 77 tests
• frontend and bridge TypeScript checks
• production frontend build and asset/manifest verification
• independent read-only diff review

No SpacetimeDB schema or player-state code changes are included.