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/components/workspace-header.tsx

@@ -0,0 +1,45 @@
+import { Link } from "react-router-dom";
+
+interface WorkspaceHeaderProps {
+  project: {
+    id: string;
+    name: string;
+    description?: string | null;
+  };
+  currentRepo?: {
+    id: string;
+    name: string;
+  } | null;
+}
+
+export const WorkspaceHeader = ({ project, currentRepo }: WorkspaceHeaderProps) => {
+  return (
+    <div className="workspace-header">
+      <div className="workspace-header-left">
+        <div className="workspace-header-icon">📁</div>
+        <div className="workspace-header-info">
+          <h1 className="workspace-header-title">{project.name}</h1>
+          {currentRepo && (
+            <span className="workspace-header-subtitle">{currentRepo.name}</span>
+          )}
+        </div>
+      </div>
+      <div className="workspace-header-actions">
+        <Link
+          className="workspace-header-action-btn"
+          to={`/projects/${project.id}/repositories/${currentRepo?.id || ""}/history`}
+        >
+          <span className="icon">🕐</span>
+          History
+        </Link>
+        <Link
+          className="workspace-header-action-btn"
+          to={`/projects/${project.id}/settings`}
+        >
+          <span className="icon">⚙️</span>
+          Settings
+        </Link>
+      </div>
+    </div>
+  );
+};