fix: cancel blocked tasks + auto-complete completion reports

Two fixes for BLOCKED task issues:

1. Allow BLOCKED → CANCELLED state transition so users can cancel tasks
   stuck waiting for input. Adds Cancel button to BLOCKED task cards in
   the UI alongside the question/answer controls.

2. Detect when agents write completion reports to $CLAUDOMATOR_QUESTION_FILE
   instead of real questions. If the question JSON has no options and no "?"
   in the text, treat it as a summary (stored on the execution) and fall
   through to normal completion + sandbox teardown rather than blocking.
   Also tightened the preamble to make the distinction explicit.

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

1 files changed, 16 insertions, 3 deletions

diff --git a/web/app.js b/web/app.js
index afb6a75..ad60f34 100644
--- a/web/app.js
+++ b/web/app.js
@@ -164,6 +164,14 @@ function createTaskCard(task) {
       footer.appendChild(rejectBtn);
     } else if (task.state === 'BLOCKED') {
       renderQuestionFooter(task, footer);
+      const cancelBtn = document.createElement('button');
+      cancelBtn.className = 'btn-cancel';
+      cancelBtn.textContent = 'Cancel';
+      cancelBtn.addEventListener('click', (e) => {
+        e.stopPropagation();
+        handleCancel(task.id, cancelBtn, footer);
+      });
+      footer.appendChild(cancelBtn);
     } else if (RESUME_STATES.has(task.state)) {
       const resumeBtn = document.createElement('button');
       resumeBtn.className = 'btn-resume';
@@ -869,8 +877,11 @@ async function handleReject(taskId, btn, footer) {
 
 // ── Start-next-task ─────────────────────────────────────────────────────────────
 
-async function startNextTask() {
-  const res = await fetch(`${API_BASE}/api/scripts/start-next-task`, { method: 'POST' });
+async function startNextTask(agent) {
+  const url = agent && agent !== 'auto'
+    ? `${API_BASE}/api/scripts/start-next-task?agent=${agent}`
+    : `${API_BASE}/api/scripts/start-next-task`;
+  const res = await fetch(url, { method: 'POST' });
   if (!res.ok) {
     let msg = `HTTP ${res.status}`;
     try { const body = await res.json(); msg = body.error || msg; } catch {}
@@ -880,10 +891,12 @@ async function startNextTask() {
 }
 
 async function handleStartNextTask(btn) {
+  const agentSelector = document.getElementById('select-agent');
+  const agent = agentSelector ? agentSelector.value : 'auto';
   btn.disabled = true;
   btn.textContent = 'Starting…';
   try {
-    const result = await startNextTask();
+    const result = await startNextTask(agent);
     const output = (result.output || '').trim();
     btn.textContent = output || 'No task to start';
     setTimeout(() => { btn.textContent = 'Start Next'; btn.disabled = false; }, 3000);