fix: Convert absolute imports to relative imports in cli modules

Fixes #193 - PDF scraping broken for PyPI users

Changed 3 files from absolute to relative imports to fix
ModuleNotFoundError when package is installed via pip:

1. pdf_scraper.py:22
   - from pdf_extractor_poc import → from .pdf_extractor_poc import
   - Fixes: skill-seekers pdf command failed with import error

2. github_scraper.py:36
   - from code_analyzer import → from .code_analyzer import
   - Proactive fix: prevents future import errors

3. test_unified_simple.py:17
   - from config_validator import → from .config_validator import
   - Proactive fix: test helper file

These absolute imports worked locally due to sys.path differences
but failed when installed via PyPI (pip install skill-seekers).

Tested with:
- skill-seekers pdf command now works ✅
- Extracted 32-page Godot Farming PDF successfully

All CLI commands should now work correctly when installed from PyPI.

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

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

src/skill_seekers/cli/github_scraper.py

@@ -33,7 +33,7 @@ except ImportError:
 
 # Import code analyzer for deep code analysis
 try:
-    from code_analyzer import CodeAnalyzer
+    from .code_analyzer import CodeAnalyzer
     CODE_ANALYZER_AVAILABLE = True
 except ImportError:
     CODE_ANALYZER_AVAILABLE = False