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/prompts.md

@@ -0,0 +1,64 @@
+# Search User Prompts
+
+Find what users have asked about in the past.
+
+## When to Use
+
+- User asks: "Have we worked on Docker before?"
+- Looking for patterns in user requests
+- Understanding what topics have been explored
+
+## Command
+
+```bash
+curl -s "http://localhost:37777/api/search/prompts?query=docker&format=index&limit=10"
+```
+
+## Parameters
+
+- **query** (required): Search terms
+- **format**: "index" (summary) or "full" (complete details). Default: "full"
+- **limit**: Number of results (default: 20, max: 100)
+- **project**: Filter by project name (optional)
+
+## Use Case
+
+"Have we worked on Docker before?" → Search prompts to see related user requests
+
+## Example Response
+
+```json
+{
+  "query": "docker",
+  "count": 3,
+  "format": "index",
+  "results": [
+    {
+      "id": 456,
+      "claude_session_id": "abc-123",
+      "prompt_number": 1,
+      "prompt_text": "Help me set up Docker for this project",
+      "created_at_epoch": 1699564800000,
+      "score": 0.98
+    }
+  ]
+}
+```
+
+## How to Present Results
+
+```markdown
+Found 3 past prompts about "docker":
+
+1. **Prompt #456** (Nov 8, 2024)
+   > "Help me set up Docker for this project"
+
+2. **Prompt #457** (Nov 9, 2024)
+   > "Fix Docker compose networking issues"
+```
+
+## Tips
+
+1. Useful for understanding what users have asked about
+2. Combine with session search to see both questions and outcomes
+3. Helps identify recurring topics or pain points