feat: MCP tools for the map-layers widget

[jean-luc-deziel]

Expose a set of MCP tools for the Bentley copilot to be able to interact with the map-layers widget. This is part of the initiative to enable the Bentley Copilot to interact with everything the user can. Including the map-layers widget. See this RFC (still in PR) for details.

The 9 tools will let the Bentley Copilot perform these actions:

• Open the map layers widget
• Toggle on/off background map
• Set base map type
• Set map transparency
• Toggle on/off terrain
• Get map layer info
• Attach a new map layer Removed for now for security concern
• Detach a map layer
• Set map layer visibility

Open question : Do we want a set of unit tests that ensure the tools are aligned with the widget. In practice, this would prevent someone from modifying the widget without updating the MCP tooling accordingly in the same PR.

In action, it would look something like that:

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull request overview

This PR adds a new MCP (Model Context Protocol) integration layer to @itwin/map-layers, enabling a Bentley copilot (via MCP) to interact with the Map Layers widget and an active iTwin.js ScreenViewport.

Changes:

• Added MCP tool functions for common map-layer/viewport operations (toggle background map, set basemap, attach/detach layers, etc.).
• Added an MCP server definition that registers those tools (stdio-oriented) and a shared viewport accessor mechanism.
• Exposed a new public subpath export @itwin/map-layers/mcp and added dependencies (@modelcontextprotocol/sdk, zod).

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
packages/itwin/map-layers/src/mcp/viewport.ts	Adds shared, settable accessor to reach the live viewport from MCP handlers.
packages/itwin/map-layers/src/mcp/tools.ts	Implements MCP-facing viewport/map-layer operations.
packages/itwin/map-layers/src/mcp/server.ts	Registers MCP tools on an McpServer and defines request schemas with Zod.
packages/itwin/map-layers/src/mcp/index.ts	Public barrel export for MCP API surface.
packages/itwin/map-layers/package.json	Adds exports entry for ./mcp and new runtime deps.
packages/itwin/map-layers/pnpm-lock.yaml	Locks new dependency graph for MCP SDK + Zod.
change/@itwin-map-layers-2eb91816-915b-4597-b434-ae4c0b597ea9.json	Declares a minor change for release notes/versioning.

Files not reviewed (1)

• packages/itwin/map-layers/pnpm-lock.yaml: Language not supported

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