Nodes: Update All Nodes — fleet-wide update request for every approved node

POST /nodes/request-update-all (admin) does what Update Node does for each
approved node: flags update_requested_at for the HTTPS updater and nudges it
over MQTT. Pending and rejected nodes are skipped. Admin-only button on the
Nodes page reports which nodes weren't reachable over MQTT.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-c2-core/app/routers/nodes.py

@@ -97,10 +97,40 @@ async def request_node_update(node_id: str, _: dict = Depends(require_admin_toke
     if not node:
         raise HTTPException(404, f"Node '{node_id}' not found.")
     requested_at = datetime.now(timezone.utc).isoformat()
+    mqtt_sent = await _flag_update(node_id, requested_at)
+    return {"ok": True, "update_requested_at": requested_at, "mqtt_sent": mqtt_sent}
+
+
+async def _flag_update(node_id: str, requested_at: str) -> bool:
     await fstore.doc_update("nodes", node_id, {"update_requested_at": requested_at})
     mqtt_sent = mqtt_handler.send_command(node_id, {"action": "node_update"})
     logger.info(f"Update requested for {node_id!r} at {requested_at} (mqtt_sent={mqtt_sent})")
-    return {"ok": True, "update_requested_at": requested_at, "mqtt_sent": mqtt_sent}
+    return mqtt_sent
+
+
+@router.post("/request-update-all")
+async def request_update_all_nodes(_: dict = Depends(require_admin_token)):
+    """Fleet-wide "Update Node": the same two-channel request as
+    request_node_update, for every approved node. Pending/rejected nodes are
+    skipped — a rejected node must not be nudged (server-26#195), and a pending
+    one has no key to check in with."""
+    requested_at = datetime.now(timezone.utc).isoformat()
+    nodes = await fstore.collection_list("nodes")
+    requested, mqtt_sent, skipped = [], [], []
+    for n in nodes:
+        nid = n.get("node_id")
+        if not nid:
+            continue
+        if n.get("approval_status") != "approved":
+            skipped.append(nid)
+            continue
+        requested.append(nid)
+        if await _flag_update(nid, requested_at):
+            mqtt_sent.append(nid)
+    logger.info(f"Fleet update requested at {requested_at}: {len(requested)} nodes, "
+                f"{len(mqtt_sent)} via MQTT, {len(skipped)} skipped")
+    return {"ok": True, "update_requested_at": requested_at, "requested": requested,
+            "mqtt_sent": mqtt_sent, "skipped": skipped}
 
 
 @router.delete("/{node_id}", status_code=204)