Photoshop 27.10 hangs opening AI-generated images (C2PA / Content Credentials validation on main thread)

Photoshop hangs (~26s, main thread unresponsive) when opening AI-generated
images containing C2PA Content Credentials. Non-AI images open normally.
Reinstalling, resetting preferences, and fixing permissions did not help.

Photoshop 27.10.0 (build 20260824.r.26), macOS 26.2 (25C56),
Mac15,7 / Apple M3 Pro / 36 GB
Crash GUID: 6837CE11-99CB-400D-A87F-506920E5830C
Dunamis Session ID: 1091910b-5f18-4726-861b-30dab874293a

Main thread, 11/11 samples, stuck in C2PA validation on import:
  __NSFireTimer (Foundation)
  ??? (Adobe Photoshop 2026 + 20931384)
  adobe_context_create_ai_compliance_workflow + 60 (libadobe_c2pa.dylib)
  ??? (libadobe_c2pa.dylib + 480580)
  ??? (libadobe_c2pa.dylib + 489032)
  ??? (libadobe_c2pa.dylib + 490712)  <- recursing ~8 levels deep
  ...
One sample shows libadobe_c2pa waiting in _dispatch_semaphore_wait_slow
(possible network/trust-list lookup on the main thread).

Secondary: the Generator thread was in vfork during the hang, briefly
blocking malloc on other threads (_xzm_fork_lock_wait).

libadobe_c2pa.dylib UUID: 29B5E8BA-F26C-3A66-B25D-981C85517E6A