feat(ccw): migrate backend to TypeScript

- Convert 40 JS files to TypeScript (CLI, tools, core, MCP server)
- Add Zod for runtime parameter validation
- Add type definitions in src/types/
- Keep src/templates/ as JavaScript (dashboard frontend)
- Update bin entries to use dist/
- Add tsconfig.json with strict mode
- Add backward-compatible exports for tests
- All 39 tests passing

Breaking changes: None (backward compatible)

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

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

.claude/agents/cli-explore-agent.md

@@ -78,14 +78,14 @@ rg "^import .* from " -n | head -30
 ### Gemini Semantic Analysis (deep-scan, dependency-map)
 
 ```bash
-cd {dir} && gemini -p "
+ccw cli exec "
 PURPOSE: {from prompt}
 TASK: {from prompt}
 MODE: analysis
 CONTEXT: @**/*
 EXPECTED: {from prompt}
 RULES: {from prompt, if template specified} | analysis=READ-ONLY
-"
+" --tool gemini --cd {dir}
 ```
 
 **Fallback Chain**: Gemini → Qwen → Codex → Bash-only