Add MCP workflow telemetry for AI plugins

[glendaviesnz]

Summary

This adds plugin-aware MCP workflow telemetry for Studio's AI integrations. This is needed so we can track usage of the Studio MCP by external agents

Changes include:

• adding a hidden studio mcp --telemetry-group <group> option so different AI plugin integrations can identify themselves when they launch the Studio MCP server
• extending the Studio CLI bump-stat types to allow plugin telemetry groups and workflow-stage stats
• adding a new record_workflow_event MCP tool that records workflow milestones like theme-build-started, theme-build-completed, and theme-build-failed
• threading the configured telemetry group through the MCP startup path so the tool can record events without the caller having to pass the plugin identity every time
• updating the Studio AI UI/system prompt metadata so the new tool is surfaced cleanly in the built-in assistant
• adding targeted MCP tool tests for configured and unconfigured telemetry behavior

This is designed to support plugin-grouped telemetry such as:

• codex-plugin + theme-build-started
• claude-code-plugin + theme-build-completed

Testing

Automated

• npm test -- apps/cli/ai/tests/tools.test.ts

Manual

1. Launch Studio MCP with a telemetry group, for example:
   • studio mcp --telemetry-group codex-plugin
2. Connect an MCP client and confirm the record_workflow_event tool is available.
3. Call the tool with:
   • workflow: theme-build
   • stage: started
4. Confirm the tool returns a success message showing the plugin group and stat name.
5. Repeat with completed and failed stages and with another workflow such as site-build.
6. Launch studio mcp without --telemetry-group and confirm the tool reports that workflow telemetry was skipped because no plugin group was configured.

Notes

• I also ran npx tsc -p apps/cli/tsconfig.json --noEmit, but it still reports an existing unrelated memfs test typing issue in apps/cli/lib/tests/snapshots.test.ts.

[wpmobilebot]

📊 Performance Test Results

Comparing f424ab3 vs trunk

app-size

Metric	trunk	f424ab3	Diff	Change
App Size (Mac)	1263.82 MB	1263.82 MB	+0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	f424ab3	Diff	Change
load	1881 ms	1559 ms	322 ms	🟢 -17.1%

site-startup

Metric	trunk	f424ab3	Diff	Change
siteCreation	8194 ms	9184 ms	+990 ms	🔴 12.1%
siteStartup	4932 ms	4952 ms	+20 ms	⚪ 0.0%

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Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)