fix: Resolve label assignment issue using dedicated Gitea API endpoint

- Update ProjectManager.set_issue_state() to use /issues/{id}/labels endpoint with PUT method
- Update ProjectManager.set_issue_priority() to use dedicated labels endpoint
- Update IssueWriter.update_labels() to use dedicated labels endpoint for reliability
- Fix API format incompatibility where issue PATCH endpoint was ignoring label updates
- Label assignment now works correctly with proper state and priority management
- Issues will now properly appear in correct Kanban columns based on status labels

Root cause: Gitea API issue PATCH endpoint silently ignores label updates, but the
dedicated labels endpoint (/issues/{id}/labels) with PUT method works correctly.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

tddai/issue_writer.py

@@ -90,8 +90,50 @@ class IssueWriter:
         return self.update_issue(issue_number, {'milestone': None})
 
     def update_labels(self, issue_number: int, labels: list) -> Dict[str, Any]:
-        """Update issue labels completely."""
-        return self.update_issue(issue_number, {'labels': labels})
+        """Update issue labels completely using dedicated labels endpoint."""
+        if not self.auth_token:
+            raise IssueError("Authentication token required for label updates")
+
+        # Use the dedicated labels endpoint which works more reliably
+        url = f"{self.config.issues_api_url}/{issue_number}/labels"
+
+        try:
+            # Use PUT to replace all labels
+            curl_cmd = [
+                'curl', '-s', '-X', 'PUT',
+                '-H', 'Content-Type: application/json',
+                '-H', f'Authorization: token {self.auth_token}',
+                '-d', json.dumps({'labels': labels}),
+                url
+            ]
+
+            result = subprocess.run(
+                curl_cmd,
+                stdout=PIPE,
+                stderr=PIPE,
+                universal_newlines=True,
+                check=True
+            )
+
+            if result.returncode != 0:
+                raise IssueError(f"Failed to update labels for issue #{issue_number}: {result.stderr}")
+
+            # Parse the response - labels endpoint returns array of labels
+            if result.stdout.strip():
+                response_data = json.loads(result.stdout)
+
+                # Convert labels response back to issue format for consistency
+                return {
+                    'number': issue_number,
+                    'labels': response_data if isinstance(response_data, list) else []
+                }
+            else:
+                return {'number': issue_number, 'labels': []}
+
+        except subprocess.CalledProcessError as e:
+            raise IssueError(f"Failed to update labels for issue #{issue_number}: {e}")
+        except json.JSONDecodeError as e:
+            raise IssueError(f"Failed to parse labels response: {e}")
 
     def add_labels(self, issue_number: int, new_labels: list) -> Dict[str, Any]:
         """Add labels to issue (preserving existing labels)."""