fix: hide console window (-H windowsgui) + wire settings/import/edit dialogs

- Add -H windowsgui ldflags so wraith.exe launches without a terminal
- Wire Settings gear button to new SettingsModal component
- Wire Import dialog to File menu and Command Palette
- Wire Connection Edit dialog to File menu, Command Palette, and context menu
- Add File menu to toolbar (New Connection, Import, Settings, Exit)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-release.yml

@@ -222,7 +222,7 @@ jobs:
 
           GOOS=windows GOARCH=amd64 CGO_ENABLED=0 \
             go build \
-              -ldflags="-s -w -X main.version=${VERSION}" \
+              -ldflags="-s -w -H windowsgui -X main.version=${VERSION}" \
               -o dist/wraith.exe \
               .