feat: Implement comprehensive IssueCreator system and create CLI roadmap issues

IssueCreator Implementation:
- Add tddai/issue_creator.py with full POST API functionality for issue creation
- Support multiple creation methods: basic, enhancement, bug, template-based
- Include structured issue formatting with acceptance criteria and dependencies
- Template system with variable substitution for reusable issue creation

Authentication Fix:
- Fix critical authentication bug: use GITEA_API_TOKEN instead of GITEA_TOKEN
- Update both IssueCreator and IssueWriter for consistency
- Update all tests and documentation to reflect correct environment variable

Comprehensive Test Suite:
- Add 15 unit tests for IssueCreator (tests/test_issue_creator.py)
- Add 5 integration tests for full API lifecycle (tests/test_issue_integration.py)
- Create test_environment_variable_detection to prevent future auth issues
- Total 33 tests covering complete issue handling workflow

CLI Integration:
- Enhance tddai_cli.py with 3 new commands: create-issue, create-enhancement, create-from-template
- Add comprehensive argument parsing with optional fields and priority support
- Include user-friendly output with next step guidance
- Update package exports to include IssueCreator

CLI Roadmap Execution:
- Successfully create 8 CLI implementation issues (#12-#19) in Gitea
- Resolve mismatch between NEXT.md roadmap and actual Gitea issues
- Issues prioritized for core USPs: Database Query CLI and AST Query CLI
- Remove local MISSING_ISSUES.md file after successful creation

Framework Maturity:
- Complete CRUD operations for issue management (Create, Read, Update, Delete)
- Robust error handling and API integration patterns
- Full authentication and environment variable management
- Ready for production CLI implementation workflow

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

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

tddai/__init__.py

@@ -7,6 +7,7 @@ Provides workspace management, test generation, and issue integration.
 
 from .workspace import WorkspaceManager, Workspace, WorkspaceStatus
 from .issue_fetcher import IssueFetcher, Issue
+from .issue_creator import IssueCreator
 from .test_generator import TestGenerator
 from .coverage_analyzer import CoverageAnalyzer, CoverageAssessment, TestRequirement, CoverageGap
 from .exceptions import TddaiError, WorkspaceError, IssueError, ConfigurationError, TestGenerationError
@@ -18,6 +19,7 @@ __all__ = [
     "WorkspaceStatus",
     "IssueFetcher",
     "Issue",
+    "IssueCreator",
     "TestGenerator",
     "CoverageAnalyzer",
     "CoverageAssessment",