Rescue work from claudomator-work: question/answer, ratelimit, start-next-task

Merges features developed in /site/doot.terst.org/claudomator-work (a
stale clone) into the canonical repo:

- executor: QuestionRegistry for human-in-the-loop answers, rate limit
  detection and exponential backoff retry (ratelimit.go, question.go)
- executor/claude.go: process group isolation (SIGKILL orphans on cancel),
  os.Pipe for reliable stdout drain, backoff retry on rate limits
- api/scripts.go: POST /api/scripts/start-next-task handler
- api/server.go: startNextTaskScript field, answer-question route,
  BroadcastQuestion for WebSocket question events
- web: Cancel/Restart buttons, question banner UI, log viewer, validate
  section, WebSocket auto-connect

All tests pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2 files changed, 137 insertions, 0 deletions

diff --git a/web/test/start-next-task.test.mjs b/web/test/start-next-task.test.mjs
new file mode 100644
index 0000000..6863f7e
--- /dev/null
+++ b/web/test/start-next-task.test.mjs
@@ -0,0 +1,84 @@
+// start-next-task.test.mjs — contract tests for startNextTask fetch helper
+// Run: node --test web/test/start-next-task.test.mjs
+
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+
+// ── Contract: startNextTask(basePath, fetchFn) ─────────────────────────────────
+// POSTs to ${basePath}/api/scripts/start-next-task
+// Returns {output, exit_code} on HTTP 2xx
+// Throws on HTTP error
+
+async function startNextTask(basePath, fetchFn) {
+  const res = await fetchFn(`${basePath}/api/scripts/start-next-task`, { method: 'POST' });
+  if (!res.ok) {
+    let msg = `HTTP ${res.status}`;
+    try { const body = await res.json(); msg = body.error || msg; } catch {}
+    throw new Error(msg);
+  }
+  return res.json();
+}
+
+describe('startNextTask', () => {
+  it('POSTs to /api/scripts/start-next-task', async () => {
+    let captured = null;
+    const mockFetch = (url, opts) => {
+      captured = { url, opts };
+      return Promise.resolve({
+        ok: true,
+        json: () => Promise.resolve({ output: 'claudomator start abc-123\n', exit_code: 0 }),
+      });
+    };
+
+    await startNextTask('http://localhost:8484', mockFetch);
+    assert.equal(captured.url, 'http://localhost:8484/api/scripts/start-next-task');
+    assert.equal(captured.opts.method, 'POST');
+  });
+
+  it('returns output and exit_code on success', async () => {
+    const mockFetch = () => Promise.resolve({
+      ok: true,
+      json: () => Promise.resolve({ output: 'claudomator start abc-123\n', exit_code: 0 }),
+    });
+
+    const result = await startNextTask('', mockFetch);
+    assert.equal(result.output, 'claudomator start abc-123\n');
+    assert.equal(result.exit_code, 0);
+  });
+
+  it('returns output when no task available', async () => {
+    const mockFetch = () => Promise.resolve({
+      ok: true,
+      json: () => Promise.resolve({ output: 'No task to start.\n', exit_code: 0 }),
+    });
+
+    const result = await startNextTask('', mockFetch);
+    assert.equal(result.output, 'No task to start.\n');
+  });
+
+  it('throws with server error message on HTTP error', async () => {
+    const mockFetch = () => Promise.resolve({
+      ok: false,
+      status: 500,
+      json: () => Promise.resolve({ error: 'script execution failed' }),
+    });
+
+    await assert.rejects(
+      () => startNextTask('', mockFetch),
+      /script execution failed/,
+    );
+  });
+
+  it('throws with HTTP status on non-JSON error response', async () => {
+    const mockFetch = () => Promise.resolve({
+      ok: false,
+      status: 503,
+      json: () => Promise.reject(new Error('not json')),
+    });
+
+    await assert.rejects(
+      () => startNextTask('', mockFetch),
+      /HTTP 503/,
+    );
+  });
+});
diff --git a/web/test/task-actions.test.mjs b/web/test/task-actions.test.mjs
new file mode 100644
index 0000000..f2c21c4
--- /dev/null
+++ b/web/test/task-actions.test.mjs
@@ -0,0 +1,53 @@
+// task-actions.test.mjs — button visibility logic for Cancel/Restart actions
+//
+// Run with: node --test web/test/task-actions.test.mjs
+
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+
+// ── Logic under test ──────────────────────────────────────────────────────────
+
+const RESTART_STATES = new Set(['FAILED', 'TIMED_OUT', 'CANCELLED']);
+
+function getCardAction(state) {
+  if (state === 'PENDING') return 'run';
+  if (state === 'RUNNING') return 'cancel';
+  if (RESTART_STATES.has(state)) return 'restart';
+  return null;
+}
+
+// ── Tests ─────────────────────────────────────────────────────────────────────
+
+describe('task card action buttons', () => {
+  it('shows Run button for PENDING', () => {
+    assert.equal(getCardAction('PENDING'), 'run');
+  });
+
+  it('shows Cancel button for RUNNING', () => {
+    assert.equal(getCardAction('RUNNING'), 'cancel');
+  });
+
+  it('shows Restart button for FAILED', () => {
+    assert.equal(getCardAction('FAILED'), 'restart');
+  });
+
+  it('shows Restart button for TIMED_OUT', () => {
+    assert.equal(getCardAction('TIMED_OUT'), 'restart');
+  });
+
+  it('shows Restart button for CANCELLED', () => {
+    assert.equal(getCardAction('CANCELLED'), 'restart');
+  });
+
+  it('shows no button for COMPLETED', () => {
+    assert.equal(getCardAction('COMPLETED'), null);
+  });
+
+  it('shows no button for QUEUED', () => {
+    assert.equal(getCardAction('QUEUED'), null);
+  });
+
+  it('shows no button for BUDGET_EXCEEDED', () => {
+    assert.equal(getCardAction('BUDGET_EXCEEDED'), null);
+  });
+});