Two independent defects made every documented 'first API call' fail:
1. FICTIONAL MODEL IDS. `zen-omni` and `zen-coder` appear ZERO times in the
live catalog (api.hanzo.ai/v1/models, 440 models). Every SDK sample -
python, typescript, go, cpp, swift, kotlin - told the customer to call a
model that does not exist, so even a correct request 400s. Corrected to the
real ids: zen5 and zen5-coder.
2. DEAD HOST + STALE PINNED MODEL. llm.hanzo.ai is retired and 301s (a POST
returns the literal string 'Permanent Redirect', not a completion), and
`claude-sonnet-4-5-20250929` is long superseded. Both removed: the host is
gone from customer-facing docs entirely rather than documented as retired,
and pinned upstream ids give way to our own current zen5.
50 files. Verified against the live catalog, not assumed.