fix: resolve MarkiTect issue handling system integration problems (issue #120)

- Fix issue manager to properly read API token and repo info from main MarkiTect config
- Update Gitea plugin to use correct repository-specific API endpoints
- Correct domain model mapping to only include valid Issue model fields
- Fix presentation layer to safely access optional body attribute
- Enable full functionality for 'markitect issues show' and 'markitect issues list' commands

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

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

markitect/issues/plugins/gitea.py

@@ -20,6 +20,11 @@ class GiteaPlugin(IssueBackend):
         """Initialize Gitea plugin with configuration."""
         super().__init__(config)
 
+        # Store repo info for API endpoints
+        self.repo_owner = config.get('repo_owner', 'coulomb')
+        self.repo_name = config.get('repo_name', 'markitect_project')
+        self.repo_full_name = f"{self.repo_owner}/{self.repo_name}"
+
         # Create connection manager with configuration
         datasource_config = DataSourceConfig(
             gitea_base_url=config.get('url', 'http://92.205.130.254:32166'),
@@ -28,7 +33,9 @@ class GiteaPlugin(IssueBackend):
         )
         connection_manager = ConnectionManager(datasource_config)
 
+        # Create repository with repo info
         self.repository = GiteaIssueRepository(connection_manager)
+        self.repository.set_repo_info(self.repo_owner, self.repo_name)
 
     def list_issues(self, state: Optional[str] = None) -> List[Issue]:
         """List issues from Gitea."""