fix(server): include registered tool icons

[Genmin]

Summary

• add icons to the high-level McpServer.registerTool() config and registered tool state
• include registered tool icons in tools/list responses
• carry the same icons option through experimental task tool registration
• add an integration regression test and a server patch changeset

Fixes #1864.

Testing

• pnpm --filter @modelcontextprotocol/server typecheck
• pnpm --filter @modelcontextprotocol/server lint
• pnpm --filter @modelcontextprotocol/test-integration lint -- test/server/mcp.test.ts
• pnpm --filter @modelcontextprotocol/test-integration test -- test/server/mcp.test.ts -t "should register tool with icons"
• pre-push hook: full Typecheck, Build, and Lint passed

[changeset-bot]

🦋 Changeset detected

Latest commit: 57b39a3

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 5 packages

Name	Type
@modelcontextprotocol/server	Patch
@modelcontextprotocol/express	Patch
@modelcontextprotocol/fastify	Patch
@modelcontextprotocol/hono	Patch
@modelcontextprotocol/node	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

Open in StackBlitz

@modelcontextprotocol/client

npm i https://pkg.pr.new/@modelcontextprotocol/client@1977

@modelcontextprotocol/server

npm i https://pkg.pr.new/@modelcontextprotocol/server@1977

@modelcontextprotocol/express

npm i https://pkg.pr.new/@modelcontextprotocol/express@1977

@modelcontextprotocol/fastify

npm i https://pkg.pr.new/@modelcontextprotocol/fastify@1977

@modelcontextprotocol/hono

npm i https://pkg.pr.new/@modelcontextprotocol/hono@1977

@modelcontextprotocol/node

npm i https://pkg.pr.new/@modelcontextprotocol/node@1977

commit: 57b39a3

[Genmin]

The remaining red check appears unrelated to this PR: test (22) failed only in test/server/cloudflareWorkers.test.ts with Miniflare returning Error: Network connection lost. All other matrix jobs and the local/pre-push validation are green after the rebase. I tried to rerun the failed job, but GitHub reports that rerunning requires repository admin rights.