feat(tool-configs): add frontend tool config management page

- Create ToolConfigsPage with tool type selector, config list, and add/edit form
- Support both env and file config types
- Add route /tool-configs and navigation item
- Update API client with tool config endpoints
- Build passes successfully

apps/web/src/router.tsx

@@ -14,6 +14,7 @@ import { RepoWorkspace } from "./pages/repo-workspace";
 import { SSHKeysPage } from "./pages/ssh-keys";
 import { SettingsPage } from "./pages/settings";
 import { TerminalPage } from "./pages/terminal";
+import { ToolConfigsPage } from "./pages/tool-configs";
 import { ToolTypesPage } from "./pages/tool-types";
 
 export const AppRouter = () => {
@@ -39,6 +40,7 @@ export const AppRouter = () => {
         <Route path="profile" element={<ProfilePage />} />
         <Route path="settings" element={<SettingsPage />} />
         <Route path="tool-types" element={<ToolTypesPage />} />
+        <Route path="tool-configs" element={<ToolConfigsPage />} />
         <Route path="instances/:instanceId/terminal" element={<TerminalPage />} />
       </Route>
       <Route path="/404" element={<NotFoundPage />} />