Update Remotion Rust FFmpeg

Require the full published rust-ffmpeg commit SHA from $update-rust-ffmpeg-sys.

Read ../pr/SKILL.md and ../pr-name/SKILL.md before committing or opening the pull request.

Prepare the worktree

Run from the dedicated Remotion worktree on codex/update-rust-ffmpeg. Never perform this work in the primary /Users/jonathanburger/remotion checkout.

Fetch origin. If the branch has no release commits yet, fast-forward it to origin/main. Do not rebase, reset, or overwrite unrelated work.

Allow this skill's own tracked .agents/skills/update-remotion-rust-ffmpeg files to exist unchanged. Stop on any pre-existing change that is not explicitly part of the requested pull request.

Verify that the supplied full SHA is reachable from remotion-dev/rust-ffmpeg's main branch. Read that commit's Cargo.toml and record the exact ffmpeg-sys-next revision for later lockfile verification.

Update Cargo and rebuild artifacts

Change only the ffmpeg-next.rev value in packages/compositor/Cargo.toml to the supplied full SHA. From packages/compositor, run: