fix: add top-level GET /workspaces endpoint and derive project/repo from workspace data

- Add all_workspaces_router with GET /workspaces/ (no project/repo required)
- Include project_id in workspace responses
- Frontend: useWorkspaces() calls listAllWorkspaces when no args
- Frontend: WorkspacesPage uses top-level list, derives project/repo from workspace for mutations
- Fixes 422 from invalid UUID path params

apps/web/src/api/workspaces.ts

@@ -22,6 +22,11 @@ export async function listWorkspaces(
 	return response.data;
 }
 
+export async function listAllWorkspaces(): Promise<Workspace[]> {
+	const response = await apiClient.get<Workspace[]>("/workspaces/");
+	return response.data;
+}
+
 export async function createWorkspace(
 	projectId: string,
 	repoId: string,