test(playwright): cover model administration lifecycle

[gbaudrit]

Summary

Adds the second squashable #291 increment: a capture-ready, offline lifecycle for the Console model provider, model profile, and runtime profile verticals. Related to #283.

Changes

• create, test, update, inspect, and delete an Ollama-backed model provider through the UI
• create, update, inspect, and delete a model profile using a model discovered from the local fake Ollama extension
• create, update, inspect, and delete a Microsoft Agent Framework runtime profile
• centralize stable editor and confirmation contracts in the model-administration page object
• add journey checkpoints, capture sample, smoke specification, and full catalog ownership for six surfaces

Validation

• npm exec tsc -- --noEmit passed
• Playwright catalog and capture CLI contracts passed: 5/5
• typed coverage reaches 55/74 surfaces (74.32%) and 72/97 routes
• full .NET build and managed-host lifecycle smoke delegated to the Browser UX CI gate because the local workspace has no .NET SDK

Breaking changes

None.