feat: Add search skill with progressive disclosure and refactor existing skills

Enhancements:
- Added search skill with 10 HTTP API endpoints for memory queries
- Refactored version-bump and troubleshoot skills using progressive disclosure pattern
- Added operations/ subdirectories for detailed skill documentation
- Updated CLAUDE.md with skill-based search architecture
- Enhanced worker service with search API endpoints
- Updated CHANGELOG.md with v5.4.0 migration details

Technical changes:
- New plugin/skills/search/ directory with SKILL.md
- New .claude/skills/version-bump/operations/ (workflow.md, scenarios.md)
- New plugin/skills/troubleshoot/operations/ (common-issues.md, worker.md)
- Modified src/services/worker-service.ts (added search endpoints)
- Modified plugin/scripts/worker-service.cjs (rebuilt with search API)
- Reduced main skill files by 89% using progressive disclosure
- Token savings: ~2,250 tokens per session start

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

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

plugin/skills/search/operations/sessions.md

@@ -0,0 +1,63 @@
+# Search Session Summaries
+
+Search session-level summaries to understand what was accomplished in past sessions.
+
+## When to Use
+
+- User asks: "What did we accomplish in previous sessions?"
+- Looking for sessions about a specific topic
+- Understanding the scope of past work
+
+## Command
+
+```bash
+curl -s "http://localhost:37777/api/search/sessions?query=deployment&format=index&limit=10"
+```
+
+## Parameters
+
+- **query** (required): Search terms (e.g., "deployment", "bug fix", "refactor")
+- **format**: "index" (summary) or "full" (complete details). Default: "full"
+- **limit**: Number of results (default: 20, max: 100)
+
+## Response Fields
+
+- **request**: Original user request
+- **completed**: What was accomplished
+- **learned**: Technical learnings
+- **next_steps**: Planned follow-ups
+- **files_read**: Files that were read
+- **files_edited**: Files that were modified
+
+## Example Use Case
+
+User asks: "Have we worked on deployment before?"
+
+```bash
+RESULT=$(curl -s "http://localhost:37777/api/search/sessions?query=deployment&format=index&limit=5")
+# Parse JSON and present matching sessions
+```
+
+## How to Present Results
+
+For format=index:
+
+```markdown
+Found 3 sessions about "deployment":
+
+1. **Session #123** (Nov 8, 2024)
+   > Deploy Docker container to production
+   > Completed: Set up CI/CD pipeline, configured secrets
+
+2. **Session #124** (Nov 9, 2024)
+   > Fix deployment rollback issues
+   > Completed: Added health checks, fixed rollback script
+```
+
+For format=full, include all fields (request, completed, learned, next_steps, files).
+
+## Tips
+
+1. Use format=index to find relevant sessions quickly
+2. Then fetch format=full for complete details
+3. Sessions capture high-level accomplishments vs observations (which are granular facts)