docs(ai-chat): align requestStop JSDoc with abort-first order (F17)

The method docstring still described the old write-then-abort order and
presented the stop_requested_at stamp as guaranteed. Reword to: abort first
(the only thing that actually stops the run), then best-effort stamp that may
be skipped on a DB error or lost to the finalize race — acceptable since the
row still settles as 'aborted'.

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

apps/server/src/core/ai-chat/ai-chat-run.service.ts

@@ -378,8 +378,11 @@ export class AiChatRunService implements OnModuleInit {
   /**
    * Request an EXPLICIT stop of a run (the user pressed Stop). This is the ONLY
    * thing that aborts a run — distinct from a browser disconnect, which leaves
-   * the run going. Records `stop_requested_at` on the row (only while active) and
-   * aborts the in-process controller if this replica owns the run. Returns true
+   * the run going. Aborts the in-process controller FIRST (the only thing that
+   * actually stops the run, if this replica owns it), then makes a best-effort
+   * attempt to stamp `stop_requested_at` — that audit write stamps only while the
+   * row is active and may be skipped on a DB error or lost to the finalize race,
+   * which is acceptable since the row still settles as 'aborted'. Returns true
    * when a stop took effect (row marked and/or controller aborted), false when
    * there was nothing active to stop.
    */