refactor: Factor out Gitea interfacing into clean facade pattern

- Create new gitea/ package with clean API facade
- Establish proper separation of concerns: tddai uses gitea, not vice versa
- Replace duplicate curl+subprocess patterns with unified HTTP client
- Add rich domain models with properties (issue.priority, issue.status)
- Maintain full backwards compatibility in tddai modules
- Reduce code complexity: -373 lines, +151 lines (net -222 lines)
- Improve testability and maintainability through clean interfaces

Architecture:
- gitea.client.GiteaClient - main facade with sub-clients
- gitea.api_client - high-level API with model conversion
- gitea.http_client - low-level HTTP operations
- gitea.models - rich domain objects (Issue, Milestone, Label)
- gitea.config - gitea-specific configuration
- gitea.exceptions - clean exception hierarchy

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

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

tddai_cli.py

@@ -691,12 +691,8 @@ def issue_index(format_type="tsv", sort_by="number", filter_state=None, filter_p
     """
     try:
         fetcher = IssueFetcher()
-        project_mgr = ProjectManager()
-        from tddai.config import get_config
         import json
 
-        config = get_config()
-
         issues = fetcher.fetch_issues()
         if not issues:
             return
@@ -704,30 +700,16 @@ def issue_index(format_type="tsv", sort_by="number", filter_state=None, filter_p
         # Collect full issue data with additional fields
         issue_data = []
         for issue in issues:
-            # Get priority and state from labels
-            priority = "none"
-            state = "none"
-            try:
-                # Use ProjectManager's API call method
-                issue_url = f"{config.issues_api_url}/{issue.number}"
-                detailed_issue = project_mgr._make_api_call('GET', issue_url)
-                labels = detailed_issue.get('labels', [])
-                priority_labels = [l['name'] for l in labels if l['name'].startswith('priority:')]
-                state_labels = [l['name'] for l in labels if l['name'].startswith('status:')]
-
-                if priority_labels:
-                    priority = priority_labels[0].replace('priority:', '')
-                if state_labels:
-                    state = state_labels[0].replace('status:', '')
-            except:
-                pass  # Keep defaults if API call fails
+            # Get priority and state from labels - now using the rich issue model
+            priority = issue.priority or "none"
+            status = issue.status or "none"
 
             issue_info = {
                 'number': issue.number,
                 'title': issue.title.replace('\t', ' ').replace('\n', ' '),  # Clean for TSV
                 'priority': priority,
                 'state': issue.state,  # open/closed from basic data
-                'status': state,  # detailed status from labels
+                'status': status,  # detailed status from labels
                 'created': issue.created_at.strftime('%Y-%m-%d'),
                 'updated': issue.updated_at.strftime('%Y-%m-%d')
             }