chore(mcp): standardize Dart MCP and add Marionette bindings

[ibrahimozkn]

Problem

Dart MCP setup was not fully standardized across agents, and Flutter apps were not wired for Marionette-based debug automation.

Changes

• Standardized repo/workspace MCP configuration for Dart tooling.
• Added Marionette MCP server entries to .mcp.json for both mcp clients sections.
• Added marionette_flutter dependency to app and designer packages.
• Updated app initialization to use MarionetteBinding.ensureInitialized() in debug mode (with Flutter test guard in app).
• Updated designer initialization to use MarionetteBinding.ensureInitialized() in debug mode.
• Included lockfile/localization formatting updates required by dependency and generator state.

Testing

• gh pr view resolves PR metadata and branch linkage.
• Branch pushed successfully with latest commits.
• Run app debug startup and verify Marionette binding initialization path.
• Run designer debug startup and verify Marionette binding initialization path.
• No regressions in MCP tooling behavior across agents.

[github-actions]

Visit the preview URL for this PR (updated for commit ec76013):

• https://studyu-dev-app--pr822-chore-setup-dart-mcp-yel66705.web.app
• https://studyu-dev-designer--pr822-chore-setup-dart-mcp-k2v2uke2.web.app

_{(expires Sun, 03 May 2026 17:24:34 GMT)}

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[mohiuddinshahrukh]

Thanks for the PR. I tested the setup on Windows.

What I checked:

• dart pub get works.
• flutter test designer_v2\test passes.
• flutter build web --debug succeeds for app.
• flutter build web --debug succeeds for designer_v2.
• dart mcp-server --help works, so the Dart MCP entry looks fine.
• dart pub global run marionette_mcp --help failed on a fresh setup until I manually ran dart pub global activate marionette_mcp.

Two suggestions if required:

1. The Marionette MCP config needs either a documented install step or a repo-managed way to run marionette_mcp.
2. .vscode/mcp.json is currently a symlink, which showed up as a plain ../.mcp.json file on my Windows checkout, so VS Code would not read it as JSON.

The app/designer builds themselves look good. I think the main thing to fix might be: making the MCP setup reproducible for someone checking out the repo fresh.

Let me know what your thoughts are!