Two bugs, both found by the first end-to-end embeddings test on a rented pod.

A capability image's entrypoint is `uvicorn codai.api.app:app` — it never runs
codai/main.py, so set_config_manager() was never called and
codai.admin.routes.config_manager stayed None. Both the CODERAI_SEED_MODELS list
and the runtime catalogue write read through that global, so a pod seeded with
one model answered "not available. Use one of: " with nothing after the colon.
The lifespan now builds its own ConfigManager when none was set — loading it is
what parses the seed list — and says how many seeds it registered.

The bearer token a pool launches its pods with is generated in memory when none
is configured. A pod that outlived the process that rented it was then adopted
with a DIFFERENT token and answered 401 for the rest of its paid life (the test
run reported serves: "(HTTP 401)"). The token is now recorded in the shared pod
registry and adopted along with the pod.

Verified live: bge-m3 on a rented RTX 2000 Ada returned a real 1024-dimension
embedding, 67.9s cold.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0182DhR1eFNPQyGmDrpHbedY