Fixes#214 - Local enhancement now handles large skills automatically
**Problem:**
- Claude CLI has undocumented ~30-40K character limit
- Large skills (>30K chars) fail silently during local enhancement
- Users experience "Claude finished but SKILL.md was not updated" error
**Solution:**
- Auto-detect large skills (>30K chars)
- Apply intelligent summarization to reduce content size
- Preserve critical content:
* First 20% (introduction/overview)
* Up to 5 best code blocks
* Up to 10 section headings with context
- Target ~30% of original size
- Show clear warnings when summarization is applied
**Implementation:**
- Added `summarize_reference()` method to LocalSkillEnhancer
- Modified `create_enhancement_prompt()` to accept summarization parameters
- Updated `run()` method to auto-enable summarization for large skills
- Added comprehensive test suite (6 tests)
**Test Results:**
- ✅ All 612 tests passing (100% pass rate)
- ✅ 6 new smart summarization tests
- ✅ E2E test: 60K skill → 17K prompt (within limits)
- ✅ Code block preservation verified
**User Experience:**
When enhancement is triggered on a large skill:
```
⚠️ LARGE SKILL DETECTED
📊 Reference content: 60,072 characters
💡 Claude CLI limit: ~30,000-40,000 characters
🔧 Applying smart summarization to ensure success...
• Keeping introductions and overviews
• Extracting best code examples
• Preserving key concepts and headings
• Target: ~30% of original size
✓ Reduced from 60,072 to 15,685 chars (26%)
✓ Prompt created and optimized (17,804 characters)
✓ Ready for Claude CLI (within safe limits)
```
**Backward Compatibility:**
- No breaking changes
- Works with existing skills
- Falls back gracefully for normal-sized skills
