AX Agent popup 시각 언어 통일 및 선택 surface 후속 정리

- 공통 popup factory가 surface visual helper를 사용하도록 정리
- worktree 선택과 권한 모드 row의 border/hover/selected 규칙을 같은 visual language로 통일
- README와 DEVELOPMENT 문서에 2026-04-06 11:27 (KST) 기준 popup polish 누적 범위 반영
- dotnet build 검증 경고 0, 오류 0 확인

docs/DEVELOPMENT.md

@@ -4937,3 +4937,5 @@ ow + toggle ?쒓컖 ?몄뼱濡??ㅼ떆 ?뺣젹?덈떎.
 - Document update: 2026-04-06 11:11 (KST) - This keeps sidebar state presentation more cohesive and further narrows the main chat window file toward orchestration-only responsibilities. Remaining work is now post-plan polish rather than another major structural split.
 - Document update: 2026-04-06 11:20 (KST) - Added `ChatWindow.SurfaceVisualPresentation.cs` and introduced shared surface helpers for popup containers, popup menu rows, separators, and file-tree headers. `ChatWindow.PreviewPresentation.cs` and `ChatWindow.FileBrowserPresentation.cs` now use the same popup/surface language instead of duplicating slightly different visual styles.
 - Document update: 2026-04-06 11:20 (KST) - This is the first visual-language polish pass after the large structure split. It reduces the feeling that preview and file browser are separate widgets and makes future popup/surface refinements reusable.
+- Document update: 2026-04-06 11:27 (KST) - Continued popup visual-language unification by switching `ChatWindow.PopupPresentation.cs` to the shared surface helpers and aligning selection/permission rows in `ChatWindow.SelectionPopupPresentation.cs` and `ChatWindow.PermissionPresentation.cs` with the same border, hover, and selected-state rules.
+- Document update: 2026-04-06 11:27 (KST) - At this point preview, file browser, worktree chooser, and permission-mode popup surfaces all share nearly the same visual language; remaining work is minor spacing/color polish rather than another behavior or structure change.