Add project-level authorization checks

Authorization:
- Add AuthorizationService for checking project access
- Implement get_user_access_level() with admin, owner, and permission checks
- Add check_project_access() helper for route handlers
- Add grant_access() and revoke_access() methods
- Add ProjectAccessChecker dependency class

Routes:
- Add authorization checks to project CRUD (read, update, delete)
- Add authorization checks to package create
- Add authorization checks to upload endpoint (requires write)
- Add authorization checks to download endpoint (requires read)
- Add authorization checks to tag create

Tests:
- Fix pagination flakiness in test_list_projects
- Fix pagination flakiness in test_projects_search
- Add API key authentication to concurrent upload test

backend/tests/integration/test_projects_api.py

@@ -59,7 +59,8 @@ class TestProjectCRUD:
     @pytest.mark.integration
     def test_list_projects(self, integration_client, test_project):
         """Test listing projects includes created project."""
-        response = integration_client.get("/api/v1/projects")
+        # Search specifically for our test project to avoid pagination issues
+        response = integration_client.get(f"/api/v1/projects?search={test_project}")
         assert response.status_code == 200
 
         data = response.json()
@@ -107,9 +108,11 @@ class TestProjectListingFilters:
     @pytest.mark.integration
     def test_projects_search(self, integration_client, test_project):
         """Test project search by name."""
-        # Search for our test project
+        # Search using the unique portion of our test project name
+        # test_project format is "test-project-test-{uuid[:8]}"
+        unique_part = test_project.split("-")[-1]  # Get the UUID portion
         response = integration_client.get(
-            f"/api/v1/projects?search={test_project[:10]}"
+            f"/api/v1/projects?search={unique_part}"
         )
         assert response.status_code == 200
 

backend/tests/integration/test_upload_download_api.py

@@ -286,6 +286,14 @@ class TestConcurrentUploads:
         expected_hash = compute_sha256(content)
         num_concurrent = 5
 
+        # Create an API key for worker threads
+        api_key_response = integration_client.post(
+            "/api/v1/auth/keys",
+            json={"name": "concurrent-test-key"},
+        )
+        assert api_key_response.status_code == 200, f"Failed to create API key: {api_key_response.text}"
+        api_key = api_key_response.json()["key"]
+
         results = []
         errors = []
 
@@ -306,6 +314,7 @@ class TestConcurrentUploads:
                         f"/api/v1/project/{project}/{package}/upload",
                         files=files,
                         data={"tag": f"concurrent-{tag_suffix}"},
+                        headers={"Authorization": f"Bearer {api_key}"},
                     )
                     if response.status_code == 200:
                         results.append(response.json())