Restore old example directories; fix typing.TypedDict on Python < 3.12

- Revert removal of examples/{clients,servers/simple-*,servers/sse-polling-demo}
  so the old examples remain alongside stories/ for now.
- schema_validators: use typing_extensions.TypedDict so pydantic accepts
  it as a tool parameter on Python 3.10/3.11.
- pyright: add explicit extraPaths for examples/servers/simple-auth — the
  mcp-example-stories editable install puts examples/ on sys.path, which
  defeats pyright's package-root auto-detection for that one example.

Author: maxisbey

examples/clients/simple-auth-client/README.md

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+# Simple Auth Client Example
+
+A demonstration of how to use the MCP Python SDK with OAuth authentication over streamable HTTP or SSE transport.
+
+## Features
+
+- OAuth 2.0 authentication with PKCE
+- Support for both StreamableHTTP and SSE transports
+- Interactive command-line interface
+
+## Installation
+
+```bash
+cd examples/clients/simple-auth-client
+uv sync --reinstall
+```
+
+## Usage
+
+### 1. Start an MCP server with OAuth support
+
+The simple-auth server example provides three server configurations. See [examples/servers/simple-auth/README.md](../../servers/simple-auth/README.md) for full details.
+
+#### Option A: New Architecture (Recommended)
+
+Separate Authorization Server and Resource Server:
+
+```bash
+# Terminal 1: Start Authorization Server on port 9000
+cd examples/servers/simple-auth
+uv run mcp-simple-auth-as --port=9000
+
+# Terminal 2: Start Resource Server on port 8001
+cd examples/servers/simple-auth
+uv run mcp-simple-auth-rs --port=8001 --auth-server=http://localhost:9000 --transport=streamable-http
+```
+
+#### Option B: Legacy Server (Backwards Compatibility)
+
+```bash
+# Single server that acts as both AS and RS (port 8000)
+cd examples/servers/simple-auth
+uv run mcp-simple-auth-legacy --port=8000 --transport=streamable-http
+```
+
+### 2. Run the client
+
+```bash
+# Connect to Resource Server (new architecture, default port 8001)
+MCP_SERVER_PORT=8001 uv run mcp-simple-auth-client
+
+# Connect to Legacy Server (port 8000)
+uv run mcp-simple-auth-client
+
+# Use SSE transport
+MCP_SERVER_PORT=8001 MCP_TRANSPORT_TYPE=sse uv run mcp-simple-auth-client
+```
+
+### 3. Complete OAuth flow
+
+The client will open your browser for authentication. After completing OAuth, you can use commands:
+
+- `list` - List available tools
+- `call <tool_name> [args]` - Call a tool with optional JSON arguments
+- `quit` - Exit
+
+## Example
+
+```markdown
+🚀 Simple MCP Auth Client
+Connecting to: http://localhost:8001/mcp
+Transport type: streamable-http
+
+🔗 Attempting to connect to http://localhost:8001/mcp...
+📡 Opening StreamableHTTP transport connection with auth...
+Opening browser for authorization: http://localhost:9000/authorize?...
+
+✅ Connected to MCP server at http://localhost:8001/mcp
+
+mcp> list
+📋 Available tools:
+1. get_time
+   Description: Get the current server time.
+
+mcp> call get_time
+🔧 Tool 'get_time' result:
+{"current_time": "2024-01-15T10:30:00", "timezone": "UTC", ...}
+
+mcp> quit
+```
+
+## Configuration
+
+| Environment Variable | Description | Default |
+|---------------------|-------------|---------|
+| `MCP_SERVER_PORT` | Port number of the MCP server | `8000` |
+| `MCP_TRANSPORT_TYPE` | Transport type: `streamable-http` or `sse` | `streamable-http` |
+| `MCP_CLIENT_METADATA_URL` | Optional URL for client metadata (CIMD) | None |

examples/clients/simple-auth-client/mcp_simple_auth_client/__init__.py

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+"""Simple OAuth client for MCP simple-auth server."""