fix: restore minimal long-task watchdog execution chain

scripts/test_long_task_watchdog.mjs

@@ -0,0 +1,159 @@
+#!/usr/bin/env node
+
+import assert from 'node:assert/strict';
+import { mkdtempSync, mkdirSync, readFileSync, rmSync, writeFileSync, readdirSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import path from 'node:path';
+import process from 'node:process';
+import { spawnSync } from 'node:child_process';
+
+const ROOT_DIR = path.resolve(import.meta.dirname, '..');
+const WATCHDOG_SCRIPT = path.join(ROOT_DIR, 'scripts', 'long_task_watchdog.mjs');
+
+function createFixtureRunner() {
+  const fixtureRoot = mkdtempSync(path.join(tmpdir(), 'long-task-watchdog-test-'));
+  const statePath = path.join(fixtureRoot, 'watchdog-state.json');
+  const evidenceDir = path.join(fixtureRoot, 'evidence');
+  mkdirSync(evidenceDir, { recursive: true });
+
+  function writeState(content) {
+    const body = typeof content === 'string' ? content : JSON.stringify(content, null, 2);
+    writeFileSync(statePath, body);
+    return statePath;
+  }
+
+  function run(args = []) {
+    const result = spawnSync(process.execPath, [WATCHDOG_SCRIPT, '--state', statePath, '--evidence-dir', evidenceDir, ...args], {
+      cwd: ROOT_DIR,
+      encoding: 'utf8',
+    });
+    return {
+      status: result.status,
+      stdout: result.stdout ?? '',
+      stderr: result.stderr ?? '',
+    };
+  }
+
+  function readState() {
+    return JSON.parse(readFileSync(statePath, 'utf8'));
+  }
+
+  function listEvidence() {
+    return readdirSync(evidenceDir).sort();
+  }
+
+  function cleanup() {
+    rmSync(fixtureRoot, { recursive: true, force: true });
+  }
+
+  return { statePath, evidenceDir, writeState, run, readState, listEvidence, cleanup };
+}
+
+const tests = [];
+function test(name, fn) { tests.push({ name, fn }); }
+
+function printResult(prefix, name, detail = '') {
+  process.stdout.write(`${prefix} ${name}${detail ? ` ${detail}` : ''}\n`);
+}
+
+test('inactive watchdogs do not emit evidence', () => {
+  const runner = createFixtureRunner();
+  try {
+    runner.writeState({
+      version: 1,
+      watchdogs: [
+        {
+          id: 'paused-watchdog',
+          task: 'paused task',
+          status: 'paused',
+          intervalMinutes: 10,
+          lastMilestoneAt: '2026-05-07T08:00:00.000Z',
+        },
+      ],
+    });
+
+    const result = runner.run(['--compact', '--now', '2026-05-07T08:20:00.000Z']);
+    assert.equal(result.status, 0, result.stderr);
+    const payload = JSON.parse(result.stdout);
+    assert.equal(payload.result.emittedCount, 0);
+    assert.deepEqual(runner.listEvidence(), []);
+  } finally {
+    runner.cleanup();
+  }
+});
+
+test('overdue active watchdog emits external evidence and updates lastAlertAt when write-state is enabled', () => {
+  const runner = createFixtureRunner();
+  try {
+    runner.writeState({
+      version: 1,
+      watchdogs: [
+        {
+          id: 'reporting-governance-plugin-watchdog',
+          task: 'reporting-governance plugin spec development',
+          status: 'active',
+          ownerSessionKey: 'agent:coder:main',
+          reportChannel: 'telegram',
+          reportTarget: '864811879',
+          intervalMinutes: 10,
+          lastMilestoneAt: '2026-05-07T08:00:00.000Z',
+          lastAlertAt: null,
+        },
+      ],
+    });
+
+    const result = runner.run(['--compact', '--write-state', '--now', '2026-05-07T08:20:00.000Z']);
+    assert.equal(result.status, 0, result.stderr);
+    const payload = JSON.parse(result.stdout);
+    assert.equal(payload.result.emittedCount, 1);
+    const evidenceFiles = runner.listEvidence();
+    assert.equal(evidenceFiles.length, 1);
+
+    const nextState = runner.readState();
+    assert.equal(nextState.watchdogs[0].lastAlertAt, '2026-05-07T08:20:00.000Z');
+  } finally {
+    runner.cleanup();
+  }
+});
+
+test('same interval is not alerted twice once lastAlertAt covers the overdue window', () => {
+  const runner = createFixtureRunner();
+  try {
+    runner.writeState({
+      version: 1,
+      watchdogs: [
+        {
+          id: 'reporting-governance-plugin-watchdog',
+          task: 'reporting-governance plugin spec development',
+          status: 'active',
+          intervalMinutes: 10,
+          lastMilestoneAt: '2026-05-07T08:00:00.000Z',
+          lastAlertAt: '2026-05-07T08:12:00.000Z',
+        },
+      ],
+    });
+
+    const result = runner.run(['--compact', '--write-state', '--now', '2026-05-07T08:15:00.000Z']);
+    assert.equal(result.status, 0, result.stderr);
+    const payload = JSON.parse(result.stdout);
+    assert.equal(payload.result.emittedCount, 0);
+    assert.deepEqual(runner.listEvidence(), []);
+  } finally {
+    runner.cleanup();
+  }
+});
+
+let failures = 0;
+for (const { name, fn } of tests) {
+  try {
+    fn();
+    printResult('ok', name);
+  } catch (error) {
+    failures += 1;
+    printResult('not ok', name, `- ${error instanceof Error ? error.message : String(error)}`);
+  }
+}
+
+if (failures > 0) {
+  process.exit(1);
+}