feat(FN-2557): expand task stats tab with execution insights

- Enrich TaskTokenStatsPanel with timing extraction, workflow runtime summaries, and longest-event highlights from task logs and workflow results
- Add an execution details section for mode, runtime status, step progress, retries, recovery state, and runtime links
- Wire TaskDetailModal to pass the working task into the stats panel so the Stats tab renders execution context with token usage
- Extend TaskDetailModal and TaskTokenStatsPanel tests (plus panel CSS) to cover the new stats sections and loading/empty/token states

packages/dashboard/app/components/__tests__/TaskTokenStatsPanel.test.tsx

@@ -1,26 +1,72 @@
 import { describe, expect, it } from "vitest";
 import { render, screen } from "@testing-library/react";
 import { TaskTokenStatsPanel } from "../TaskTokenStatsPanel";
+import type { Task } from "@fusion/core";
+
+function makeTask(overrides: Partial<Task> = {}): Task {
+  return {
+    id: "FN-400",
+    description: "Stats panel task",
+    column: "in-progress",
+    dependencies: [],
+    steps: [{ name: "One", status: "done" }, { name: "Two", status: "in-progress" }],
+    currentStep: 1,
+    log: [
+      { timestamp: "2026-04-24T09:00:00.000Z", action: "[timing] Worktree init command completed in 120ms" },
+      { timestamp: "2026-04-24T09:01:00.000Z", action: "Started execution" },
+      { timestamp: "2026-04-24T09:02:00.000Z", action: "[timing] [verification] test command succeeded (exit 0) in 3400ms" },
+    ],
+    workflowStepResults: [
+      {
+        workflowStepId: "WS-001",
+        workflowStepName: "QA Check",
+        status: "passed",
+        startedAt: "2026-04-24T09:10:00.000Z",
+        completedAt: "2026-04-24T09:10:07.000Z",
+      },
+    ],
+    status: "executing",
+    paused: false,
+    executionMode: "fast",
+    recoveryRetryCount: 1,
+    workflowStepRetries: 2,
+    mergeRetries: 3,
+    taskDoneRetryCount: 4,
+    stuckKillCount: 1,
+    postReviewFixCount: 2,
+    assignedAgentId: "agent-1",
+    checkedOutBy: "executor-1",
+    blockedBy: "FN-300",
+    sessionFile: ".fusion/sessions/FN-400.json",
+    createdAt: "2026-04-24T09:00:00.000Z",
+    updatedAt: "2026-04-24T09:30:00.000Z",
+    ...overrides,
+  };
+}
 
 describe("TaskTokenStatsPanel", () => {
   it("renders loading state while task detail token usage is hydrating", () => {
-    render(<TaskTokenStatsPanel loading tokenUsage={undefined} />);
+    render(<TaskTokenStatsPanel loading tokenUsage={undefined} task={makeTask()} />);
 
+    expect(screen.getByText("Execution Timing")).toBeInTheDocument();
+    expect(screen.getByText("Execution Details")).toBeInTheDocument();
+    expect(screen.getByText("Token Usage")).toBeInTheDocument();
     expect(screen.getByText("Loading token statistics…")).toBeInTheDocument();
     expect(screen.queryByText("No token usage recorded for this task yet.")).toBeNull();
   });
 
-  it("renders empty state when detail is loaded without usage", () => {
-    render(<TaskTokenStatsPanel loading={false} tokenUsage={undefined} />);
+  it("renders empty token state when detail is loaded without usage", () => {
+    render(<TaskTokenStatsPanel loading={false} tokenUsage={undefined} task={makeTask()} />);
 
     expect(screen.getByText("No token usage recorded for this task yet.")).toBeInTheDocument();
     expect(screen.queryByText("Loading token statistics…")).toBeNull();
   });
 
-  it("renders all token totals and usage timestamps", () => {
+  it("renders execution timing, details, and token totals", () => {
     render(
       <TaskTokenStatsPanel
         loading={false}
+        task={makeTask()}
         tokenUsage={{
           inputTokens: 1200,
           outputTokens: 450,
@@ -32,6 +78,13 @@ describe("TaskTokenStatsPanel", () => {
       />,
     );
 
+    expect(screen.getByText("Timing events")).toBeInTheDocument();
+    expect(screen.getByText("Workflow runtime")).toBeInTheDocument();
+    expect(screen.getByText("Execution mode")).toBeInTheDocument();
+    expect(screen.getByText("Fast")).toBeInTheDocument();
+    expect(screen.getByText("Runtime status")).toBeInTheDocument();
+    expect(screen.getByText("executing")).toBeInTheDocument();
+
     expect(screen.getByText("Input")).toBeInTheDocument();
     expect(screen.getByText("Output")).toBeInTheDocument();
     expect(screen.getByText("Cached")).toBeInTheDocument();
@@ -47,4 +100,20 @@ describe("TaskTokenStatsPanel", () => {
     expect(firstUsedTime).toBeInTheDocument();
     expect(lastUsedTime).toBeInTheDocument();
   });
+
+  it("gracefully handles logs without timing patterns", () => {
+    render(
+      <TaskTokenStatsPanel
+        loading={false}
+        tokenUsage={undefined}
+        task={makeTask({
+          log: [{ timestamp: "2026-04-24T09:00:00.000Z", action: "Non timing entry" }],
+          workflowStepResults: [],
+        })}
+      />,
+    );
+
+    expect(screen.getByText("No timed events recorded yet.")).toBeInTheDocument();
+    expect(screen.getByText("No completed workflow step timings yet.")).toBeInTheDocument();
+  });
 });