fix: Update test imports and merge_sources for v2.0.0 release

- Fix conflict_detector import in merge_sources.py (use relative import)
- Update test_mcp_server.py to use skill_seekers.mcp.server imports
- Fix @patch decorators to reference full module path
- Add MCP_AVAILABLE guards to test_unified_mcp_integration.py
- Add proper skipif decorators for MCP tests
- All 379 tests now passing (0 failures)

Resolves import errors that occurred during PyPI package testing.

src/skill_seekers/cli/merge_sources.py

@@ -16,7 +16,7 @@ import tempfile
 import os
 from pathlib import Path
 from typing import Dict, List, Any, Optional
-from conflict_detector import Conflict, ConflictDetector
+from .conflict_detector import Conflict, ConflictDetector
 
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__name__)