feat: Merge PR #249 - Bootstrap skill with fixes and MCP optionality

Merged PR #249 from @MiaoDX with enhancements:

Bootstrap Feature:
- Self-bootstrap: Generate skill-seekers as Claude Code skill
- Robust frontmatter detection (dynamic line finding)
- SKILL.md validation (YAML + Markdown structure)
- Comprehensive error handling (uv check, permission checks)
- 6 E2E tests with venv isolation

MCP Optionality (User Feature):
- MCP removed from core dependencies
- Optional install: pip install skill-seekers[mcp]
- Lazy loading with helpful error messages
- Interactive setup wizard on first run
- Backward compatible

Bug Fixes:
- Fixed codebase_scraper.py AttributeError (line 1193)
- Fixed test_bootstrap_skill_e2e.py Path vs str issue
- Updated test version expectations to 2.7.0
- Added httpx to core (required for async scraping)
- Added anthropic to core (required for AI enhancement)

Testing:
- 6 new bootstrap E2E tests (all passing)
- 1207/1217 tests passing (99.2% pass rate)
- All bootstrap and enhancement tests pass
- Remaining failures are pre-existing test infrastructure issues

Documentation:
- Updated CHANGELOG.md with v2.7.0 notes
- Updated README.md with bootstrap and installation options
- Added setup wizard guide

Files Modified (9):
- CHANGELOG.md, README.md - Documentation updates
- pyproject.toml - MCP optional, httpx/anthropic core, markers, entry points
- scripts/bootstrap_skill.sh - Dynamic frontmatter, validation, error handling
- src/skill_seekers/cli/install_skill.py - Lazy MCP loading
- tests/test_cli_paths.py - Version 2.7.0
- uv.lock - Dependency updates

New Files (2):
- src/skill_seekers/cli/setup_wizard.py - Interactive installation guide (95 lines)
- tests/test_bootstrap_skill_e2e.py - E2E bootstrap tests (169 lines)

Credits: @MiaoDX for PR #249

Co-Authored-By: MiaoDX <MiaoDX@hotmail.com>
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tests/test_cli_paths.py

@@ -126,7 +126,7 @@ class TestUnifiedCLIEntryPoints(unittest.TestCase):
 
             # Should show version
             output = result.stdout + result.stderr
-            self.assertIn('2.5.1', output)
+            self.assertIn('2.7.0', output)
 
         except FileNotFoundError:
             # If skill-seekers is not installed, skip this test