refactor: Address PR comments

- Extract tool results rendering into separate ToolResults component
- Hoist checkContentCompatibility function to module level following codebase conventions
- Add ajv@6.12.6 as direct dependency to client package.json
- All tests pass and linting is clean

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

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

client/package.json

@@ -25,6 +25,7 @@
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.11.5",
     "@radix-ui/react-checkbox": "^1.1.4",
+    "ajv": "^6.12.6",
     "@radix-ui/react-dialog": "^1.1.3",
     "@radix-ui/react-icons": "^1.3.0",
     "@radix-ui/react-label": "^2.1.0",