The last two gaps from the person-to-scene audit.

IP-Adapter on the video path never worked. _apply_character_refs() set
kw['ip_adapter_image'] without ever calling load_ip_adapter(), so a pipeline that
does accept the kwarg (AnimateDiff) failed inside diffusers rather than
transferring identity, and it also passed ip_adapter_scale as a call kwarg, which
no pipeline accepts — a second latent TypeError. It now reuses the image path's
_ensure_ip_adapter_loaded(), sets the scale through set_ip_adapter_scale(), and
returns whether conditioning is actually active. Pipelines with no IP-Adapter at
all (Wan/CogVideoX/LTX/SVD) now say so instead of looking like they worked.

Lip sync required a 'wav2lip' or 'sadtalker' executable on PATH — a file that
essentially never exists, since Wav2Lip ships neither a pip package nor a binary
and its original checkpoint links are dead. codai/api/lipsync.py now owns the
lifecycle the way ds4_worker owns ds4: it fetches code AND weights from the
camenduru/Wav2Lip mirror on first use, patches what no longer runs on modern
numpy/librosa/torch, creates the scratch dirs inference.py expects, and drives it
as a subprocess. An operator-installed binary still takes precedence.

Each patched file is compiled before being kept, so a bad rewrite is caught at
patch time and reverted rather than surfacing as a SyntaxError from a subprocess
(which is exactly how the first attempt failed: two librosa patterns compounded
into 'sr=sr=').

Lip-sync fallback is no longer silent. The reason travels up a per-request
warnings list — not module state, which would cross-talk between concurrent
requests — and appears as a `warnings` field on the video response, so a client can tell
a synchronised result from a plain audio mux.

Verified offline (live container untouched): Wav2Lip downloads, patches, and
lip-syncs a real face to audio, producing a valid 768x512 h264+aac mp4 that
differs from the source; the second run reuses the install with no download;
the fallback populates warnings; IP-Adapter loads its weights and sets the scale
for a supporting pipeline and cleanly declines for a Wan-like one.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R6iugoNeEgt9PkajKrFyq4