Problem: a clip set to play backward (`clip.speedDuration` with
`reverse: true`) read back from `sequence.inspect` exactly like a
forward clip: same `speed`, same source range, nothing that said it was
reversed. An agent could set it and not confirm it.
Solution: clips gain `reverse` (bool) in `sequence.inspect`, named as
in the project file and in the command. Additive; existing keys are
unchanged. `docs/agents.md` lists it and says what it means for the
source range.
Tests: sequence_inspect_tests.rs reverses a demo clip through the
command and checks that only that clip reports `reverse: true`, and
none after undo.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>