Merge remote-tracking branch 'origin/master' into dev

Resolve conflicts in the export pipeline where dev's job-queue refactor
met master's chapter-metadata and security work.

- Unify chapter support under ChaptersEnum (none / recording_segments /
  review_items); the realtime stream-copy export selects the per-segment
  or per-review-item builder by the camera's configured mode. Thread
  chapters through ExportRecordingsBody -> _build_export_job -> ExportJob
  -> RecordingExporter.
- Keep master's creation_time/comment export metadata and fix a
  video_path duplication the textual merge introduced in the preview
  command.
- Move the chapters request field to ExportRecordingsBody (the single
  export endpoint) where it is actually honored.

Restore security fixes the automatic merge would have reverted:
- frigate/util/services.py: restore the #23493 rename to the public
  is_go2rtc_arbitrary_exec_allowed so create_config.py's dynamic-source
  exec guard imports and runs (the merge otherwise left a broken import).
- Preserve the export image-path ".." traversal check inside
  _sanitize_existing_image, applied to single/custom/batch exports.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/public/locales/en/config/cameras.json

@@ -493,6 +493,9 @@
       "max_concurrent": {
         "label": "Maximum concurrent exports",
         "description": "Maximum number of export jobs to process at the same time."
+      },
+      "chapters": {
+        "label": "Chapter metadata to embed in exported recordings"
       }
     },
     "preview": {