feat: add MCP roots protocol support to everything server

- Add roots capability declaration with listChanged: true
- Implement roots/list_changed notification handler
- Add initialization handler to request initial roots from client
- Add new listRoots tool to demonstrate roots functionality
- Add comprehensive logging for roots protocol events
- Update README.md with roots documentation

Resolves #2552

The everything server now demonstrates all MCP features including the roots protocol.
This provides a complete reference implementation for client developers to test
their roots protocol implementation against, even though this server doesn't
access files directly.

src/everything/README.md

@@ -89,6 +89,13 @@ This MCP server attempts to exercise all the features of the MCP protocol. It is
      - `structuredContent` field conformant to the output schema
      - A backward compatible Text Content field, a SHOULD advisory in the specification
 
+11. `listRoots`
+   - Lists the current MCP roots provided by the client
+   - Demonstrates the roots protocol capability even though this server doesn't access files
+   - No inputs required
+   - Returns: List of current roots with their URIs and names, or a message if no roots are set
+   - Shows how servers can interact with the MCP roots protocol
+
 ### Resources
 
 The server provides 100 test resources in two formats:
@@ -129,6 +136,18 @@ Resource features:
    - Returns: Multi-turn conversation with an embedded resource reference
    - Shows how to include resources directly in prompt messages
 
+### Roots
+
+The server demonstrates the MCP roots protocol capability:
+
+- Declares `roots: { listChanged: true }` capability to indicate support for roots
+- Handles `roots/list_changed` notifications from clients
+- Requests initial roots during server initialization
+- Provides a `listRoots` tool to display current roots
+- Logs roots-related events for demonstration purposes
+
+Note: This server doesn't actually access files, but demonstrates how servers can interact with the roots protocol for clients that need to understand which directories are available for file operations.
+
 ### Logging
 
 The server sends random-leveled log messages every 15 seconds, e.g.: