Add new PTSL commands (PT 2025.06+): Import/Spot/CreateAudioClips/BounceTrack

[Shimagon]

TL;DR

Adds 4 new PTSL command IDs that became available in Pro Tools 2025.06+ to src/grpc/commands.ts — enum entries plus their permission-group mappings. Nothing else.

What's added

Command	ID	Group	Purpose
ImportAudioToClipList	123	TRACK_STRUCTURE	Import WAV/AIFF into the session Clip List without the import dialog
SpotClipsByID	124	TRACK_STRUCTURE	Place clips on a track at a given timecode (by clip ID)
CreateAudioClips	127	TRACK_STRUCTURE	Create audio clips from audio files (companion to SpotClipsByID)
BounceTrack	134	EXPORT	Render a single track to a file (per-track stem export)

The three TRACK_STRUCTURE commands together unlock a programmatic "drop pre-rendered stems onto tracks at known timecodes" workflow, which is the bottleneck for any AI-assisted arrangement tooling on top of PTSL.

BounceTrack is grouped under EXPORT because it writes a new audio file to disk; it should be gated by the same ALLOW_WRITES=export flag as ExportMix / ExportClipsAsFiles.

Scope discipline

This PR is intentionally enum-only. The following are deferred to separate follow-up PRs so each can be reviewed independently:

• The high-level bounce_track MCP tool wrapper (UX layer — name, args, error messages, ALLOW_WRITES gate test).
• The streaming event-subscription commands SubscribeToEvents (132), PollEvents (135), UnsubscribeFromEvents (136) — these need streaming RPC plumbing and a subscribe_events / poll_events / unsubscribe_events MCP tool surface, which deserves its own review.
• The error-payload sanitization work (drop session_id / file paths from surfaced PTSL errors) flagged in Critical: state-mutating commands wrongly classified as READ_ONLY (ALLOW_WRITES bypass) #1 as out-of-scope.

This PR also has zero overlap with #1 (the READ_ONLY_COMMANDS bypass fix); they touch different lines and can be merged in either order.

Verification

• npm install && npm run build (tsc) passes cleanly on this branch.
• Permission-group placement was sanity-checked against the existing groupings: ImportAudioToClipList / SpotClipsByID / CreateAudioClips mutate session structure (clip references in the .ptx), so they belong with CreateNewTracks under TRACK_STRUCTURE. BounceTrack writes a file to disk, so it belongs with ExportMix / ExportClipsAsFiles under EXPORT.
• ID values come from the public PTSL.proto shipped with Pro Tools 2025.06; command_id numbers themselves are not copyrighted.

Marked draft because the maintainer may prefer a different grouping for ImportAudioToClipList (arguments could be made for a new IMPORT group, or for CLIPBOARD) — happy to rename / regroup before merge. Also waiting to confirm the maintainer wants the events-tool work as a separate follow-up vs. bundled.