Expand profile inspection metadata

[KingAkeem]

What changed

• Request the useful public X user fields supported by the current integration.
• Return identifiers as strings and expose profile media, verification, protection, entities, location, website, pinned/recent post IDs, and public metrics.
• Add readiness and configuration-aware error responses instead of surfacing missing credentials as opaque failures.
• Translate X provider failures into actionable responses, including depleted credits, rate limits, invalid access, and missing profiles.

Why

Profile inspection previously returned a narrow record and failed unclearly when the bearer token was unavailable. The richer contract gives the desktop workspace useful investigation context while keeping configuration problems actionable.

Validation

• Covered by the platform FastAPI regression suite, including X provider error mapping.
• Verified through the nginx /focus/readyz route with the configured X credential.