Expose get_app_metrics (uptime, latency, error rate) via the MCP

Complementary to get_app_logs — I need platform-level metrics that the builder never writes to entities: uptime, P50/P95 latency, request count, error rate, active user count per app.

Requested primitive:

• get_app_metrics({ appId, timeRange }) — returns standard ops metrics for the app

Today I'd have to open each app's dashboard one by one. At 135 apps, an MCP endpoint is essential for programmatic health rollups across the portfolio.

Thank you.