e689351597
- Centralized OAuth access lifecycle in `AuthStorage`, returning identity metadata and new access-result types. - Added 60-second skew and strict expiry checks, returning undefined/throws for stale or expired OAuth credentials. - Removed provider-local token refresh flows from Gemini, Gemini CLI, Antigravity, Kimi, and related OAuth helpers. - Migrated web-search providers from `AgentStorage` to `AuthStorage` session-aware lookup with `authStorage`/`sessionId`/`signal` flow. - Replaced `findAnthropicAuth`/DB auth lookup with `buildAnthropicAuthConfig` and explicit base-url override/env fallback ordering.