The agent could already draw, animate and wire graphs, but songs, patterns, sound clips and compositions were out of its reach. This last step of #429 adds the two missing catalog areas, so the agent can now use 168 of the editor's commands. - Area music (15 commands): notes, pattern and song loops, song tracks and items, sends, and clips of sounds and videos. - Area composition (9 commands): tracks, items for objects, images and audio, changes with fades, volume and bus, removal, and animation clips. - A pitch is a MIDI number or a name like C4 or F#3. A note past the end of its pattern is refused. - Song and master routing stay graphs. The agent links them with connect, and set_send sets level and tap. get_graph now shows the send of every link. - Lengths follow the same rules as dragging in the tab. A sound has a length only after the editor loaded it. get_asset reports it as seconds, and without it the agent has to give a length. - Moving a composition item takes its clips along, as dragging does. A clip that would then overlap another one is refused. Fades are only allowed on items with sound. - get_asset reads notes back with their names and gives the length of a pattern in ticks. Found while testing live: two song tracks in the same column made lint_graph report a backwards link. arrange_graph cleared it, as the agent instructions ask. Tests: - agent-music (new, 9 tests) and the other agent and relay tests: 109/109. - 9 mutations of the new code, each one red in its own test. - e2e 71 on melektaus-atx: 25/25. New check: notes are read back by name, and a composition with a pattern and a sprite opens in its tab. - Gate on melektaus-atx: CHECK EXIT 0, 323 files, 4987 tests. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>