feat(admin): Owner column on All Users' Events card

Adds the event's wallet owner (user_id) as the first column of the
admin-only All Users' Events table so cross-tenant rows are
attributable at a glance. Server-side join: GET /events/all now
resolves each event.wallet -> wallet.user and stamps the result on
the response as wallet_user_id. Frontend gets a dedicated
allUsersEventsTable.columns definition so the user's own-events
table stays unchanged.

Follow-up #22 covers letting the admin actually edit those events
once attributed.

views_api.py

@@ -101,9 +101,22 @@ async def api_events_public() -> list[Event]:
 @events_api_router.get("/all")
 async def api_events_all(
     admin: Account = Depends(check_admin),
-) -> list[Event]:
-    """All events across all wallets. LNbits admin only."""
-    return await get_all_events()
+) -> list[dict]:
+    """All events across all wallets, with each row's wallet owner
+    resolved to a user_id. LNbits admin only.
+
+    Returns dicts (not strict `Event` rows) so the response can carry
+    the synthetic `wallet_user_id` column the admin UI uses to attribute
+    each cross-tenant event to a user.
+    """
+    events = await get_all_events()
+    enriched: list[dict] = []
+    for event in events:
+        wallet = await get_wallet(event.wallet)
+        row = event.dict()
+        row["wallet_user_id"] = wallet.user if wallet else None
+        enriched.append(row)
+    return enriched
 
 
 @events_api_router.get("/pending")