feat: make MCP SDK a peer dependency (#168)

* feat: make MCP SDK a peer dependency

- Move @modelcontextprotocol/sdk from dependencies to peerDependencies (^1.20.0)
- Add to devDependencies for local development (^1.24.3)
- Externalize SDK from all build entry points (app, app-bridge, react, server)

Benefits:
- Consumers control their SDK version
- Deduplication when consumer already has SDK
- Follows pattern of react/zod peer deps

* fix: require SDK ^1.24.0 for Zod 4 compatibility

Earlier SDK versions have Zod type incompatibilities that cause build errors.

* chore: update examples to SDK ^1.24.0 to match peer dep

package.json

@@ -59,12 +59,11 @@
   },
   "author": "Olivier Chafik",
   "devDependencies": {
+    "@modelcontextprotocol/sdk": "^1.24.0",
     "@playwright/test": "^1.52.0",
     "@types/bun": "^1.3.2",
     "@types/react": "^19.2.2",
     "@types/react-dom": "^19.2.2",
-    "react": "^19.2.0",
-    "react-dom": "^19.2.0",
     "concurrently": "^9.2.1",
     "cors": "^2.8.5",
     "cross-env": "^10.1.0",
@@ -72,6 +71,8 @@
     "express": "^5.1.0",
     "husky": "^9.1.7",
     "nodemon": "^3.1.0",
+    "react": "^19.2.0",
+    "react-dom": "^19.2.0",
     "ts-to-zod": "^5.1.0",
     "tsx": "^4.21.0",
     "typedoc": "^0.28.14",
@@ -79,6 +80,7 @@
     "zod": "^4.1.13"
   },
   "peerDependencies": {
+    "@modelcontextprotocol/sdk": "^1.24.0",
     "react": "^17.0.0 || ^18.0.0 || ^19.0.0",
     "react-dom": "^17.0.0 || ^18.0.0 || ^19.0.0",
     "zod": "^3.25.0 || ^4.0.0"
@@ -92,7 +94,6 @@
     }
   },
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.24.3",
     "prettier": "^3.6.2"
   },
   "optionalDependencies": {