feat(FN-4199): complete Step 2 — extend agents stats capacity counts

Fusion-Task-Id: FN-4199
Fusion-Task-Lineage: fd530f3d-ef2e-4684-ab05-5aaab6856f15

packages/dashboard/src/__tests__/routes-agents.test.ts

@@ -4250,6 +4250,47 @@ describe("Agent stale task-link sanitization", () => {
     expect(res.body.assignedTaskCount).toBe(0);
   });
 
+  it("GET /api/agents/stats returns idle non-ephemeral and todo counts", async () => {
+    const store = createMockStore({
+      getFusionDir: vi.fn().mockReturnValue(fusionDir),
+      listTasks: vi.fn().mockResolvedValue([
+        { id: "FN-1", column: "todo" },
+        { id: "FN-2", column: "todo" },
+        { id: "FN-3", column: "triage" },
+        { id: "FN-4", column: "in-progress" },
+        { id: "FN-5", column: "in-review" },
+        { id: "FN-6", column: "done" },
+      ]),
+    } as any);
+
+    const app = express();
+    app.use(express.json());
+    app.use("/api", createApiRoutes(store));
+
+    const { AgentStore } = await import("@fusion/core");
+    const agentStore = new AgentStore({ rootDir: fusionDir });
+    await agentStore.init();
+
+    const idleNonEphemeral = await agentStore.createAgent({ name: "Idle Exec", role: "executor" });
+    await agentStore.updateAgentState(idleNonEphemeral.id, "idle");
+
+    const idleEphemeral = await agentStore.createAgent({
+      name: "executor-ephemeral",
+      role: "executor",
+      metadata: { type: "spawned" },
+    });
+    await agentStore.updateAgentState(idleEphemeral.id, "idle");
+
+    const active = await agentStore.createAgent({ name: "Active Exec", role: "executor" });
+    await agentStore.updateAgentState(active.id, "active");
+
+    const res = await GET(app, "/api/agents/stats");
+
+    expect(res.status).toBe(200);
+    expect(res.body.idleNonEphemeralCount).toBe(1);
+    expect(res.body.todoTaskCount).toBe(2);
+  });
+
   it("GET /api/agents handles task lookup failure gracefully", async () => {
     const taskId = "FN-LOOKUP-FAIL";
     const store = createMockStore({

packages/dashboard/src/routes/register-agent-core-routes.ts

@@ -6,6 +6,7 @@ import {
   ApprovalRequestStore,
   getDefaultHeartbeatProcedurePath,
   isAgentPermissionPolicyPresetId,
+  isEphemeralAgent,
   normalizeAgentPermissionPolicyFromPreset,
 } from "@fusion/core";
 import { ApiError, badRequest, notFound } from "../api-error.js";
@@ -268,6 +269,7 @@ export function registerAgentCoreRoutes(ctx: ApiRoutesContext, deps: AgentCoreRo
    * Return aggregate stats across all agents.
    * Must be registered before /agents/:id to avoid "stats" matching :id.
    * Note: assignedTaskCount excludes agents whose linked task is in a terminal state.
+   * Includes idleNonEphemeralCount and todoTaskCount to back capacity-risk signaling.
    */
   router.get("/agents/stats", async (req, res) => {
     try {
@@ -278,6 +280,7 @@ export function registerAgentCoreRoutes(ctx: ApiRoutesContext, deps: AgentCoreRo
 
       const agents = await agentStore.listAgents();
       const activeCount = agents.filter((a) => a.state === "active" || a.state === "running").length;
+      const idleNonEphemeralCount = agents.filter((a) => a.state === "idle" && !isEphemeralAgent(a)).length;
 
       // Count only agents with non-terminal linked tasks
       const sanitizedAgents = await sanitizeAgentTaskLinks(agents, scopedStore);
@@ -293,7 +296,17 @@ export function registerAgentCoreRoutes(ctx: ApiRoutesContext, deps: AgentCoreRo
 
       const total = completedRuns + failedRuns;
       const successRate = total > 0 ? completedRuns / total : 0;
-      res.json({ activeCount, assignedTaskCount, completedRuns, failedRuns, successRate });
+      const tasks = await scopedStore.listTasks({ slim: true, includeArchived: false });
+      const todoTaskCount = tasks.filter((task) => task.column === "todo").length;
+      res.json({
+        activeCount,
+        assignedTaskCount,
+        completedRuns,
+        failedRuns,
+        successRate,
+        idleNonEphemeralCount,
+        todoTaskCount,
+      });
     } catch (err: unknown) {
       if (err instanceof ApiError) {
         throw err;