fix(server): support two-arg no-schema task handlers

[Genmin]

What changed

Fixes #1471 by allowing no-input-schema task handlers to receive task context as the second argument when they are written in the common (_args, ctx) form.

The executor still preserves the existing context-only (ctx) path for no-schema handlers, so current TypeScript users are not forced into a breaking runtime change. The public task handler types now accept either no-schema shape, while schema-backed handlers remain (args, ctx) as before.

Why

registerToolTask currently calls no-schema createTask handlers with a single context argument. JavaScript users, or users bypassing types, can naturally write async createTask(_args, ctx), which previously received ctx as undefined and failed before creating a task.

Validation

• pnpm --filter @modelcontextprotocol/server exec vitest run test/server/mcp.tasks.test.ts
• pnpm --filter @modelcontextprotocol/server typecheck
• pnpm --filter @modelcontextprotocol/server lint
• pre-push hook: pnpm -r typecheck, pnpm -r build, pnpm sync:snippets --check, pnpm -r lint

[changeset-bot]

🦋 Changeset detected

Latest commit: 4411b7e

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

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[pkg-pr-new]

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@modelcontextprotocol/client

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@modelcontextprotocol/express

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@modelcontextprotocol/fastify

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commit: 4411b7e

[Genmin]

Pushed a focused follow-up for the build failure. The no-schema task callback helper is now inlined into the exported handler aliases so TypeDoc no longer sees a private referenced type.

Validation:

• pnpm run docs:check
• pnpm --filter @modelcontextprotocol/server typecheck
• pnpm --filter @modelcontextprotocol/server lint
• pnpm --filter @modelcontextprotocol/server test -- --run packages/server/test/server/mcp.tasks.test.ts
• pre-push hook: build, lint, typecheck all passed

[Genmin]

Checked the remaining failing job. The Deno runtime check is failing before repo install/test execution while denoland/setup-deno downloads Deno v2.7.14 from GitHub releases:

Unexpected HTTP response: 500

All repo build/typecheck/lint/test jobs are green after the follow-up commit, so this looks transient/infrastructure rather than a code failure.