- Added `.trellis/tasks/04-17-deep-code-review-ocswitch/review.md` to capture the full deep review output and concrete remediation guidance.
- Recorded 2 high-risk items:
  - concurrent config/OpenCode save paths are unsafe under concurrent writers
  - proxy request body has no read timeout after headers
- Recorded 4 medium-risk items:
  - streaming responses have no idle timeout
  - retryable upstream failures are collapsed into a generic `502`
  - `opencode sync --set-model` / `--set-small-model` can silently write invalid defaults
  - fixed default API key remains unsafe when binding to non-loopback addresses
- Recorded 4 low-risk or improvement items:
  - alias lifecycle lacks enable/disable recovery path
  - provider import docs and implementation disagree on empty `apiKey`
  - `opencode sync` side effects on JSONC comments and `$schema` need clearer docs
  - header forwarding should better handle dynamic hop-by-hop headers and narrower forwarding rules
- Implemented direct fixes for the clearly scoped items:
  - added advisory file locking and atomic writes for both local config and OpenCode sync writes
  - validated non-loopback server binds cannot keep the default local API key
  - added routable alias validation for `opencode sync --set-model` and `--set-small-model`
  - added request body read timeout handling and stable timeout error mapping
  - added stream idle timeout and last retryable upstream error passthrough for `429`/`5xx`
  - narrowed forwarded request headers conservatively, including dynamic `Connection`-declared hop-by-hop removal
  - aligned provider import behavior/docs to allow empty `apiKey`
  - documented that OpenCode sync rewrites JSONC as normalized JSON
- Verification completed after implementation:
  - `go test ./...`
  - `go test -race ./...`