docs: add local development MCP client configuration to READMEs (#361)

* docs: add local development MCP client configuration to READMEs

Add instructions for configuring MCP clients to use locally-cloned
and modified servers. This allows developers to test local changes
with MCP clients like Claude Desktop or VS Code.

- Top-level README: Added 'Local Development' section after npx config
- All TypeScript examples: Added 'Local Development' subsection with
  bash one-liner that builds and runs the server
- Python examples (qr-server, say-server): Added local path config

* docs: include all servers in local development config

* docs: use bash wrapper for Python server configs to enable tilde expansion

examples/basic-server-react/README.md

@@ -28,6 +28,21 @@ Add to your MCP client configuration (stdio transport):
 }
 ```
 
+### Local Development
+
+To test local modifications, use this configuration (replace `~/code/ext-apps` with your clone path):
+
+```json
+{
+  "mcpServers": {
+    "basic-react": {
+      "command": "bash",
+      "args": ["-c", "cd ~/code/ext-apps/examples/basic-server-react && npm run build >&2 && node dist/index.js --stdio"]
+    }
+  }
+}
+```
+
 ## Overview
 
 - Tool registration with a linked UI resource