## Why
Guardian Decisions requests used bearer keys directly, bypassing runtime authentication. Memory startup quota checks used the app-level auth manager instead of the thread's provider auth context.
## What changed
- Bind Decisions credentials to runtime authentication and use route-aware HTTP clients with sensitive header protection. Preserve workload identity credentials, reuse the saved-login runtime binding, and isolate explicit API key bindings.
- Select the staging Decisions endpoint when the ChatGPT environment is staging.
- Use the thread's `ProviderAuthContext` for memory startup and quota checks, preserving account-bound network policy and applying runtime authentication.
- Keep custom destinations independent of runtime assertions.
## Testing
Add regression tests for dual-header and assertion-only authentication, fresh Decisions assertions, saved versus explicit credential isolation, workload identity, staging routing, redirect header protection, and memory quota authentication with custom destinations.
GitOrigin-RevId: 27bc7821a1cad1f5d1d2a71680527ea91ace95db
## What changed
- Use the shared runtime and effective configuration for account API clients and remote plugin requests, including standalone plugin commands.
- Support dual-header and assertion-only authentication for remote plugins and MCP file uploads when runtime agent instances are enabled.
- Keep plugin credentials and caches scoped to the thread's account when resuming with different credentials. Bind request pools and multi-step plugin storage operations to the selected account so account replacement revokes stale operations.
- Protect runtime credentials on cross-origin redirects while preserving configured routing policies and legacy authentication for custom backends.
- Apply server-provided `upload_headers` to file storage uploads.
## Testing
Add coverage for shared runtime registration, both authentication modes, configuration reloads, resumed-thread account selection, account replacement during plugin uploads and downloads, and credential stripping on redirects. Extend file upload tests to verify runtime assertions and storage-only upload headers.
GitOrigin-RevId: 68aef81051a6f9bf919fffda52f372b108fce805
cooper-oai