fix: clamp fractional automation queue limits

lib/automation-control.js

@@ -21,8 +21,8 @@
     if (isString && value.trim() === '') return 15000;
     const number = Number(value);
     if (!Number.isFinite(number) || number < 0) return 15000;
-    if (number === 0 && isString && value.trim() !== '0') return 15000;
-    return Math.floor(number);
+    if (number === 0) return isString && value.trim() !== '0' ? 15000 : 0;
+    return Math.max(1, Math.floor(number));
   }
 
   function normalizeAutomationSettings(value = {}) {

tests/automation-control.test.js

@@ -59,6 +59,13 @@ test('automation settings allow only numeric and trimmed string zero to disable
   assert.equal(normalizeAutomationSettings({ queueLimitJobs: ' 0 ' }).queueLimitJobs, 0);
 });
 
+test('automation settings clamp positive queue limit fractions to one', () => {
+  assert.deepEqual(
+    [0.5, '0.5', 0.125].map((queueLimitJobs) => normalizeAutomationSettings({ queueLimitJobs }).queueLimitJobs),
+    [1, 1, 1]
+  );
+});
+
 test('capacity counts only executable and running queue jobs', () => {
   const statuses = ['preview', 'queued', 'getting-server', 'uploading', 'retrying', 'done', 'error', 'aborted', 'skipped'];
   assert.equal(countAutomaticQueueJobs(statuses.map((status, index) => ({ id: String(index), status }))), 5);
@@ -146,6 +153,20 @@ test('admission allows only numeric and trimmed string zero to disable the queue
   );
 });
 
+test('admission keeps positive queue limit fractions bounded to one job', () => {
+  const candidate = { path: 'two-jobs.mkv', mtimeMs: 1, eligibleJobCount: 2 };
+  assert.deepEqual(
+    [0.5, '0.5', 0.125].map((queueLimitJobs) => planAtomicAdmissions({ candidates: [candidate], queueLimitJobs })),
+    [0.5, '0.5', 0.125].map(() => ({
+      admittedPaths: [],
+      deferredPaths: ['two-jobs.mkv'],
+      currentJobCount: 0,
+      plannedJobs: 0,
+      availableSlots: 1
+    }))
+  );
+});
+
 test('daily telemetry resets atomically on the local calendar day boundary', () => {
   const before = { dateKey: '2026-08-25', detected: 8, queued: 4, skipped: 2, deferred: 1 };
   const now = new Date(2026, 7, 26, 0, 0, 1).getTime();