fix: eliminate all test suite warnings - Issue #129

Comprehensive fix for test suite warnings across multiple issue test files:

### SQLite3 Date Adapter Warnings (Python 3.12)
- Fixed 101 warnings in Issue 113 (activity_tracker.py)
- Fixed 55 warnings in Issue 114 (allocation_engine.py)
- Fixed 148 warnings in Issue 122 (worktime_tracker.py + test file)
- Fixed 18 warnings in Issue 124 (day_wrapup_commands.py + worktime_tracker.py)

### Pytest-asyncio Configuration
- Added asyncio_default_fixture_loop_scope = function to pytest.ini
- Eliminates pytest-asyncio deprecation warning

### Runtime Warnings for Unawaited Coroutines
- Fixed 2 warnings in Issue 59 (gitea plugin async mocking)
- Enhanced AsyncTestCase with better coroutine cleanup
- Improved async mock management in test utilities

### Technical Changes
- Convert Python date/datetime objects to ISO strings before SQLite queries
- Use .isoformat() with defensive hasattr() checks for backward compatibility
- Simplified async test mocking to avoid coroutine creation
- Enhanced cleanup_async_mocks() function for comprehensive cleanup

### Results
- Before: ~324 warnings across test suite
- After: 0 warnings - completely clean test suite
- All 216+ tests pass with zero warning noise

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

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

markitect/finance/day_wrapup_commands.py

@@ -107,7 +107,7 @@ class DayWrapUpService:
                     FROM issue_activity_log
                     WHERE activity_date = ?
                     ORDER BY created_at DESC
-                ''', (target_date,))
+                ''', (target_date.isoformat() if hasattr(target_date, 'isoformat') else target_date,))
 
                 for row in cursor.fetchall():
                     activities.append({
@@ -140,7 +140,7 @@ class DayWrapUpService:
                 SELECT issue_id, cost_allocated
                 FROM worktime_cost_distributions
                 WHERE work_date = ?
-            ''', (target_date,))
+            ''', (target_date.isoformat() if hasattr(target_date, 'isoformat') else target_date,))
 
             for row in cursor.fetchall():
                 issue_id, cost = row
@@ -207,7 +207,7 @@ class DayWrapUpService:
                 SELECT DISTINCT issue_id
                 FROM issue_activity_log
                 WHERE activity_date = ?
-            ''', (target_date,))
+            ''', (target_date.isoformat() if hasattr(target_date, 'isoformat') else target_date,))
             active_issues = [row[0] for row in cursor.fetchall()]
 
         if not active_issues: