feat: add project settings page with tabbed layout

- Create SettingsTabLayout component with sidebar navigation
- Create ProjectSettingsPage with General settings tab
- Create RepositoriesSettingsTab for repo management
- Add Members placeholder tab
- Update router with settings routes
- Add CSS styles for settings layout
- Navigate to /projects/:id/settings from workspace header

apps/web/src/router.tsx

@@ -8,6 +8,7 @@ import { ProfilePage } from "./pages/profile";
 import { ProjectsPage } from "./pages/projects";
 import { GitRepositoriesPage } from "./pages/git-repositories";
 import { GitHistoryPage } from "./pages/git-history";
+import { ProjectSettingsPage } from "./pages/project-settings";
 import { RepoWorkspace } from "./pages/repo-workspace";
 import { SSHKeysPage } from "./pages/ssh-keys";
 import { SettingsPage } from "./pages/settings";
@@ -30,6 +31,7 @@ export const AppRouter = () => {
         <Route path="projects/:projectId" element={<RepoWorkspace />} />
         <Route path="projects/:projectId/repositories" element={<GitRepositoriesPage />} />
         <Route path="projects/:projectId/repositories/:repoId/history" element={<GitHistoryPage />} />
+        <Route path="projects/:projectId/settings/*" element={<ProjectSettingsPage />} />
         <Route path="ssh-keys" element={<SSHKeysPage />} />
         <Route path="profile" element={<ProfilePage />} />
         <Route path="settings" element={<SettingsPage />} />