The video pipeline is reused across clips (model CPU offload keeps weights in host
RAM), so the per-request teardown that trims the heap — _free_pipeline_vram ->
_trim_cpu_ram — never runs between clips. Each generation allocs ~1 GB of
decode/latent/offload buffers; Python frees them but glibc keeps the pages in its
arena, so RSS drifts up clip-by-clip (seen ~34 -> 47 GB) and peaks over the
max_ram_gb cap. The cap can't reclaim it: the only resident model is the protected
live one, so there's nothing idle to evict (and ram_leak_watch is off).

Fix: after each successful generation, drop the decode buffers (frames/frame_np),
gc, and malloc_trim the freed heap back to the OS. Logs RSS before/after so a
RESIDUAL reference leak (RSS not returning to baseline after trim) is visible to
chase separately. Failure paths already trim via _free_pipeline_vram.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RdMufYvtTbtGDWsiZVoXce