feat(commons): project outbound API/DB/notification rows onto the External lane

ResolveKind maps ApiOutbound/DbOutbound/Notification to ApiCall/DbCall/Notify;
ResolveLane puts the three on FlowLane.External; outbound outcomes map
Delivered→Ok, Failed→Failed, Parked/Discarded→Parked, else Pending; subtitles
'{status} · sync|cached', '{op} · n rows' from a DbWrite Extra, '{status}' for
Notify. New FlowStepProjector.IsOutbound helper.

Claude-Session: https://claude.ai/code/session_01NcMG6xXdsJbmD2wYAgkK29

docs/plans/2026-09-06-flow-debugger-outbound-calls.md.tasks.json

@@ -4,12 +4,12 @@
     {
       "id": 0,
       "subject": "Task 0: Commons \u2014 kinds, lane, outcomes, lifecycle row",
-      "status": "pending"
+      "status": "completed"
     },
     {
       "id": 1,
       "subject": "Task 1: Commons \u2014 FlowStepProjector maps outbound rows",
-      "status": "pending",
+      "status": "in_progress",
       "blockedBy": [
         0
       ]
@@ -96,5 +96,5 @@
       ]
     }
   ],
-  "lastUpdated": "2026-09-06T05:32:15.141670+00:00"
-}
+  "lastUpdated": "2026-09-06T05:37:29.919766+00:00"
+}