fix(launcher): open_in_os win routing, display override, and onsite ext fix

- open_in_os='win' now routes to Windows launch profiles (pptxwin/pptwin/odpwin/pdfwin)
  via WIN_EXTENSION_MAP in get_launch_profile() — was silently ignored before
- Display override migrated from non-existent cfg_json backend field to localStorage
  ($events_loc.launcher.file_display_overrides) — only visible in edit mode; TODO added
  for proper backend column when event_file gains cfg_json
- Onsite mode WIN extension rename now covers all 4 types (pptx, ppt, odp, pdf)
  instead of only pptx/ppt
- open_in_os button shows LoaderCircle spinner during API call
- Remove cfg_json from properties_to_save (column does not exist on event_file table)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/ae_events/ae_events__event_file.ts

@@ -539,7 +539,6 @@ export const properties_to_save = [
     'filename',
     'extension',
     'open_in_os',
-    'cfg_json',
     'lu_file_purpose_id',
     'lu_event_file_purpose_name',
     'file_purpose',