#22458: Codex/macos chat corner clip

## Summary Describe the problem and fix in 2–5 bullets: - Problem: - Why it matters: - What changed: - What did NOT change (scope boundary): ## Change Type (select all) - [ ] Bug fix - [ ] Feature - [ ] Refactor - [ ] Docs - [ ] Security hardening - [ ] Chore/infra ## Scope (select all touched areas) - [ ] Gateway / orchestration - [ ] Skills / tool execution - [ ] Auth / tokens - [ ] Memory / storage - [ ] Integrations - [ ] API / contracts - [ ] UI / DX - [ ] CI/CD / infra ## Linked Issue/PR - Closes # - Related # ## User-visible / Behavior Changes List user-visible changes (including defaults/config). If none, write `None`. ## Security Impact (required) - New permissions/capabilities? (`Yes/No`) - Secrets/tokens handling changed? (`Yes/No`) - New/changed network calls? (`Yes/No`) - Command/tool execution surface changed? (`Yes/No`) - Data access scope changed? (`Yes/No`) - If any `Yes`, explain risk + mitigation: ## Repro + Verification ### Environment - OS: - Runtime/container: - Model/provider: - Integration/channel (if any): - Relevant config (redacted): ### Steps 1. 2. 3. ### Expected - ### Actual - ## Evidence Attach at least one: - [ ] Failing test/log before + passing after - [ ] Trace/log snippets - [ ] Screenshot/recording - [ ] Perf numbers (if relevant) ## Human Verification (required) What you personally verified (not just CI), and how: - Verified scenarios: - Edge cases checked: - What you did **not** verify: ## Compatibility / Migration - Backward compatible? (`Yes/No`) - Config/env changes? (`Yes/No`) - Migration needed? (`Yes/No`) - If yes, exact upgrade steps: ## Failure Recovery (if this breaks) - How to disable/revert this change quickly: - Files/config to restore: - Known bad symptoms reviewers should watch for: ## Risks and Mitigations List only real risks for this PR. Add/remove entries as needed. If none, write `None`. - Risk: - Mitigation: <!-- greptile_comment --> <h3>Greptile Summary</h3> Fixed corner clipping in macOS WebChat panel by adjusting the visual effect view's blending mode and applying matching corner styling to the hosting view layer. - Changed `effectView.blendingMode` from always `.behindWindow` to conditionally use `.withinWindow` for panels and `.behindWindow` for windows - Added `backgroundColor = NSColor.clear.cgColor` to the effect view layer - Applied corner curve, corner radius, and masking to the hosting view layer to match the effect view configuration This ensures proper rendering of rounded corners for the panel presentation mode without visual artifacts. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk - The changes are narrowly scoped to visual rendering configuration for the macOS WebChat UI. The logic conditionally applies presentation-specific styles using a switch expression on an existing enum, and the new layer properties (corner curve, radius, masking) are applied consistently to both the effect view and hosting view. Existing tests cover both window and panel presentation modes. - No files require special attention _{Last reviewed commit: 1922e99} <!-- greptile_other_comments_section --> _{(3/5) Reply to the agent's comments like "Can you suggest a fix for this @greptileai?" or ask follow-up questions!} <!-- /greptile_comment -->