fix: allow workspace creation from workspaces page

- Replace awkward first-workspace-guessing logic with inline project/repo selector
- New WorkspaceCreateInline component with cascading dropdowns:
  - Select project → loads repositories for that project
  - Select repository → enter workspace name + branch
  - Submit creates workspace via top-level POST /workspaces/
- Add createWorkspaceTopLevel() API client for flat endpoint
- Works even with zero existing workspaces (shows create button in empty state)
- Add CSS grid layout for inline create form
- TypeScript + eslint clean

apps/web/src/api/workspaces.ts

@@ -39,6 +39,13 @@ export async function createWorkspace(
 	return response.data;
 }
 
+export async function createWorkspaceTopLevel(
+	data: CreateWorkspaceRequest & { repo_id: string },
+): Promise<Workspace> {
+	const response = await apiClient.post<Workspace>("/workspaces/", data);
+	return response.data;
+}
+
 export async function getWorkspace(
 	projectId: string,
 	repoId: string,