read a model's card where the card actually lives

Adding `defaults` to the Z-Image-Turbo entry showed they would have been
ignored anyway.

The manager keeps runtime kwargs FLAT and the models.json entry under
`_raw_cfg`, so only keys that `build_runtime_kwargs` promotes exist at the top
level — and `defaults` is not one of them. `model_defaults()` read the flat
dict, so on the image path a card's steps and guidance were silently dropped:
`/v1/models` published them (it reads the entry) while generation used the
generic 30 steps at CFG 7.5. A client that read the listing and trusted the
server to apply it was wrong twice over.

Which means `Z-Image-Turbo-IntoRealism` (10 steps) and `Krea-2-RealDream` (8)
had never had their cards applied, and `call_kwargs` sits in the same place —
MOSS-Image's `uncond_skip_layers` was never passed either.

`card_view()` merges the entry under the flat kwargs, with the flat ones
winning a collision because they are what the loader was given, and both
readers go through it. The video path had already hit this and merged by hand
at its call site; `images.py` never did, and one of the two being right is
what made it invisible. Same lesson as the `gpu_split` and
`sequential_text_encoder` promotions, three lines apart in that same function.

The new test walks the installed catalogue and asserts, for every card
carrying `defaults`, that what the listing publishes is what generation would
use.

Also: a TTS engine's venv no longer reports itself ready on the strength of
the engine package alone. `pip install coqui-tts` brought ninety dependencies
and no torch, the venv looked complete, `/v1/audio/speech/capabilities` said
`env_ready: true`, and the first synthesis failed on `import TTS`. `torch` is
in every family's list now.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014T3rZozi1Ehk96NG1WesgC