feat(frontend): Add trigger agent banner for webhook-based flows (#11480)

This PR addresses the need for better user awareness when building
trigger-based agents. When a user adds webhook/trigger nodes to their
flow, a prominent banner now appears at the bottom of the builder
informing them they're creating a "Trigger Agent" and providing a direct
link to monitor its activity in the Agent Library.

### Changes 🏗️

- **Added TriggerAgentBanner component**: New banner that displays at
the bottom of the builder when the flow contains webhook/trigger nodes
- **Implemented webhook node detection**: Added `hasWebhookNodes` method
to nodeStore that checks if any nodes are of type WEBHOOK or
WEBHOOK_MANUAL
- **Conditional banner display**: Builder now shows TriggerAgentBanner
instead of BuilderActions when webhook nodes are present
- **Dynamic library link**: Banner includes a link to the specific agent
in the library (if found) or defaults to the general library page
- **Integrated with existing flow context**: Uses the current flowID to
fetch the corresponding library agent for proper linking

### Checklist 📋

#### For code changes:
- [x] I have clearly listed my changes in the PR description
- [x] I have made a test plan
- [x] I have tested my changes according to the test plan:
  - [x] Add a webhook node to a flow and verify the banner appears
  - [x] Remove all webhook nodes and verify the banner disappears
  - [x] Test with both WEBHOOK and WEBHOOK_MANUAL node types
- [x] Click the library link and verify it navigates to the correct
agent page
  - [x] Test library link fallback when agent is not found in library
- [x] Verify banner styling and positioning at bottom center of builder

autogpt_platform/frontend/src/app/(platform)/build/components/FlowEditor/Flow/Flow.tsx

@@ -16,6 +16,7 @@ import { useCopyPaste } from "./useCopyPaste";
 import { FloatingReviewsPanel } from "@/components/organisms/FloatingReviewsPanel/FloatingReviewsPanel";
 import { parseAsString, useQueryStates } from "nuqs";
 import { CustomControls } from "./components/CustomControl";
+import { TriggerAgentBanner } from "./components/TriggerAgentBanner";
 
 export const Flow = () => {
   const [{ flowExecutionID }] = useQueryStates({
@@ -27,6 +28,9 @@ export const Flow = () => {
   const onNodesChange = useNodeStore(
     useShallow((state) => state.onNodesChange),
   );
+  const hasWebhookNodes = useNodeStore(
+    useShallow((state) => state.hasWebhookNodes()),
+  );
   const nodeTypes = useMemo(() => ({ custom: CustomNode }), []);
   const edgeTypes = useMemo(() => ({ custom: CustomEdge }), []);
   const { edges, onConnect, onEdgesChange } = useCustomEdge();
@@ -76,7 +80,7 @@ export const Flow = () => {
           <Background />
           <CustomControls setIsLocked={setIsLocked} isLocked={isLocked} />
           <NewControlPanel />
-          <BuilderActions />
+          {hasWebhookNodes ? <TriggerAgentBanner /> : <BuilderActions />}
           {<GraphLoadingBox flowContentLoading={isFlowContentLoading} />}
           {isGraphRunning && <RunningBackground />}
         </ReactFlow>

autogpt_platform/frontend/src/app/(platform)/build/components/FlowEditor/Flow/components/TriggerAgentBanner.tsx

@@ -0,0 +1,49 @@
+import {
+  Alert,
+  AlertDescription,
+  AlertTitle,
+} from "@/components/molecules/Alert/Alert";
+import Link from "next/link";
+import { useGetV2GetLibraryAgentByGraphId } from "@/app/api/__generated__/endpoints/library/library";
+import { LibraryAgent } from "@/app/api/__generated__/models/libraryAgent";
+import { useQueryStates, parseAsString } from "nuqs";
+
+export const TriggerAgentBanner = () => {
+  const [{ flowID }] = useQueryStates({
+    flowID: parseAsString,
+  });
+
+  const { data: libraryAgent } = useGetV2GetLibraryAgentByGraphId(
+    flowID ?? "",
+    {},
+    {
+      query: {
+        select: (x) => {
+          return x.data as LibraryAgent;
+        },
+        enabled: !!flowID,
+      },
+    },
+  );
+
+  return (
+    <Alert className="absolute bottom-4 left-1/2 z-20 w-auto -translate-x-1/2 select-none rounded-xlarge">
+      <AlertTitle>You are building a Trigger Agent</AlertTitle>
+      <AlertDescription>
+        Your agent will listen for its trigger and will run when the time is
+        right.
+        <br />
+        You can view its activity in your{" "}
+        <Link
+          href={
+            libraryAgent ? `/library/agents/${libraryAgent.id}` : "/library"
+          }
+          className="underline"
+        >
+          Agent Library
+        </Link>
+        .
+      </AlertDescription>
+    </Alert>
+  );
+};

autogpt_platform/frontend/src/app/(platform)/build/stores/nodeStore.ts

@@ -44,6 +44,7 @@ type NodeStore = {
   ) => void;
   getNodeExecutionResult: (nodeId: string) => NodeExecutionResult | undefined;
   getNodeBlockUIType: (nodeId: string) => BlockUIType;
+  hasWebhookNodes: () => boolean;
 };
 
 export const useNodeStore = create<NodeStore>((set, get) => ({
@@ -204,4 +205,9 @@ export const useNodeStore = create<NodeStore>((set, get) => ({
       BlockUIType.STANDARD
     );
   },
+  hasWebhookNodes: () => {
+    return get().nodes.some((n) =>
+      [BlockUIType.WEBHOOK, BlockUIType.WEBHOOK_MANUAL].includes(n.data.uiType),
+    );
+  },
 }));