Add VST2->VST3/AU preset recovery for dead VST2 plugins

macOS dropping VST2 leaves old projects with non-loading plugins whose
preset state still lives in the .als. This adds tooling to recover it:

- preset_port.py: low-level state porting (VST3 ProcessorState chunk copy,
  AU .aupreset plist editing for soundhack FXP / u-he AM_STATE, in-place
  VST2->VST3 device conversion), lossless gzip+XML round-trip.
- track_ops.py: Ableton-faithful track duplication. ID model reverse-
  engineered from Live 12's own duplicates (only pointee-space defs get
  fresh sequential ids, only PointeeId refs rewritten, locals kept).
- device_templates.py: installed VST3/AU matcher + device-node template
  harvester (project then library, cached).
- recover.py + scripts/recover_vst2.py: analyze/recover CLI. Duplicates
  affected tracks as '- COMPAT', swaps plugins, ports state. Incompatible
  cases (e.g. Reaktor CSAR v5 vs v6) are reported with a recall hint,
  never silently broken. Originals untouched; safety backup before write.