Third-party Anthropic-compatible providers can expose Claude model names without supporting every first-party runtime capability. Desktop sessions now preserve provider-specific capability overrides, keep selected provider runtime state across reconnects and restarts, and keep the provider dialog behavior aligned with the updated presets.
Constraint: Custom ANTHROPIC_BASE_URL endpoints must not be treated as first-party Anthropic for adaptive thinking support.
Rejected: Rename provider default Sonnet models | that would hide the compatibility issue instead of fixing runtime capability detection.
Confidence: high
Scope-risk: moderate
Directive: Do not enable Claude first-party capability defaults for custom Anthropic-compatible base URLs without provider verification.
Tested: bun test src/utils/__tests__/thinking.test.ts src/server/__tests__/conversation-service.test.ts src/server/__tests__/provider-presets.test.ts src/server/__tests__/conversations.test.ts
Tested: cd desktop && bun run lint
Tested: cd desktop && bun run test src/components/shared/Modal.test.tsx --run
Tested: git diff --check
