fix(web): drop dead no-arg listTasks + invalidate overview on runtime-limit WS

Per #143 review (REQUEST_CHANGES), two fixes:

1. Must-fix #1 — bare listTasks() URL /tasks/tasks:
   The retained no-arg overload did request(`${API_BASE}/tasks`) while
   API_BASE is already '/tasks' (regression re-introduced when migrating files
   off an older branch state). After the dashboard migrated to /projects/overview,
   the no-arg path has no remaining caller, so the overload + bare branch are
   removed entirely. listTasks(projectId) is the only signature now.

2. Must-fix #2 — WS runtime_limit_updated leaves overview metrics stale:
   project:runtime_limit_updated fired but only invalidated ['tasks'], skipping
   the new overview query. Since overview aggregates token/cost fields, the
   dashboard header + project cards showed stale token/cost after usage updates.
   Add invalidateProjectTaskOverviews(queryClient) in that branch.

Regression test: useWebSocketOverviewInvalidation.test pins that
invalidateProjectTaskOverviews invalidates ['projectTaskOverviews'], so a
future change that drops/renames the query key surfaces immediately.

Verification: tsc clean (web); 675 web tests green; prettier/lint/build green.

Author: ichinya

packages/web/src/__tests__/useWebSocketOverviewInvalidation.test.ts

@@ -0,0 +1,25 @@
+import { describe, it, expect, vi } from "vitest";
+import { QueryClient } from "@tanstack/react-query";
+import { invalidateProjectTaskOverviews } from "@/hooks/useProjects";
+
+/**
+ * Regression for the WS overview-invalidation gap (#143 review, must-fix #2).
+ *
+ * `project:runtime_limit_updated` fires when persisted runtime-limit / last
+ * usage state changes. The overview aggregates token/cost fields, so this
+ * event must invalidate the `["projectTaskOverviews"]` query — otherwise the
+ * dashboard header and project cards show stale token/cost after usage
+ * updates. The useWebSocket handler calls `invalidateProjectTaskOverviews`
+ * (from useProjects) in that branch; this test pins that helper so a future
+ * change that drops or renames the query key surfaces immediately.
+ */
+describe("invalidateProjectTaskOverviews (WS runtime_limit_updated branch)", () => {
+  it("invalidates the projectTaskOverviews query", () => {
+    const queryClient = new QueryClient();
+    const invalidateSpy = vi.spyOn(queryClient, "invalidateQueries");
+
+    invalidateProjectTaskOverviews(queryClient);
+
+    expect(invalidateSpy).toHaveBeenCalledWith({ queryKey: ["projectTaskOverviews"] });
+  });
+});

packages/web/src/hooks/useWebSocket.ts

@@ -227,6 +227,8 @@ export function useWebSocket() {
           pendingTaskIds.current.add(data.payload.taskId);
           queryClient.invalidateQueries({ queryKey: ["tasks"] });
         }
+        // Overview aggregates token/cost fields, so refresh after usage updates.
+        invalidateProjectTaskOverviews(queryClient);
         return;
       }
 

packages/web/src/lib/api.ts

@@ -254,16 +254,12 @@ async function request<T>(
   return res.json();
 }
 
-// Task list fetch. Overloaded: bare listTasks() returns full Task[] (legacy
-// dashboard path, until consumers migrate to GET /projects/overview);
-// listTasks(projectId) returns lightweight TaskListItem[] (board/list).
-function listTasks(): Promise<Task[]>;
-function listTasks(projectId: string): Promise<TaskListItem[]>;
-function listTasks(projectId?: string): Promise<Task[] | TaskListItem[]> {
-  if (projectId === undefined) {
-    console.debug("[api] GET /tasks (bare, legacy)");
-    return request<Task[]>(`${API_BASE}/tasks`);
-  }
+// Task list fetch. projectId is required: the board/list view is always scoped.
+// The dashboard moved to GET /projects/overview (see #139), so the bare no-arg
+// listTasks() path has no remaining caller and is removed. The server route
+// still answers bare requests for backward compatibility, but the web client
+// never calls it.
+function listTasks(projectId: string): Promise<TaskListItem[]> {
   const qs = `?projectId=${encodeURIComponent(projectId)}`;
   console.debug("[api] GET /tasks?projectId=%s", projectId);
   return request<TaskListItem[]>(`${API_BASE}${qs}`);