refactor: Update CLI commands to use new unified entry points

Updated all command examples in CLI scripts from old pattern:
  python3 cli/<script>.py → skill-seekers <command>

Changes:
- doc_scraper.py → skill-seekers scrape
- github_scraper.py → skill-seekers github
- pdf_scraper.py → skill-seekers pdf
- unified_scraper.py → skill-seekers unified
- enhance_skill.py → skill-seekers enhance
- enhance_skill_local.py → skill-seekers enhance
- package_skill.py → skill-seekers package
- estimate_pages.py → skill-seekers estimate

This reflects the new modern Python packaging with proper entry
points. Users can now use clean commands instead of file paths.

Files updated: 10 CLI scripts

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

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

src/skill_seekers/cli/pdf_scraper.py

@@ -195,7 +195,7 @@ class PDFToSkillConverter:
         self._generate_skill_md(categorized)
 
         print(f"\n✅ Skill built successfully: {self.skill_dir}/")
-        print(f"\n📦 Next step: Package with: python3 cli/package_skill.py {self.skill_dir}/")
+        print(f"\n📦 Next step: Package with: skill-seekers package {self.skill_dir}/")
 
     def _generate_reference_file(self, cat_key, cat_data):
         """Generate a reference markdown file for a category"""