feat: stuck detection — alerts when same files repeat 3x

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

tests/test_stuck.py

@@ -0,0 +1,55 @@
+import sys
+sys.path.insert(0, 'bin')
+from stuck_check import is_stuck
+
+def test_not_stuck_with_different_files():
+    entries = [
+        {'project': 'x', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['b.go']},
+        {'project': 'x', 'files_changed': ['c.go']},
+    ]
+    assert is_stuck('x', entries) is False
+
+def test_stuck_when_same_files_3_times():
+    entries = [
+        {'project': 'x', 'files_changed': ['a.go', 'b.go']},
+        {'project': 'x', 'files_changed': ['a.go', 'b.go']},
+        {'project': 'x', 'files_changed': ['a.go', 'b.go']},
+    ]
+    assert is_stuck('x', entries) is True
+
+def test_not_stuck_with_fewer_than_3_entries():
+    entries = [
+        {'project': 'x', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['a.go']},
+    ]
+    assert is_stuck('x', entries) is False
+
+def test_only_checks_matching_project():
+    entries = [
+        {'project': 'y', 'files_changed': ['a.go']},
+        {'project': 'y', 'files_changed': ['a.go']},
+        {'project': 'y', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['a.go']},
+    ]
+    assert is_stuck('x', entries) is False  # only 2 entries for x
+
+def test_not_stuck_when_files_empty():
+    """Empty file sets don't count as stuck — agent may not have changed anything."""
+    entries = [
+        {'project': 'x', 'files_changed': []},
+        {'project': 'x', 'files_changed': []},
+        {'project': 'x', 'files_changed': []},
+    ]
+    assert is_stuck('x', entries) is False
+
+def test_order_matters_only_last_3():
+    """Only the last 3 entries matter."""
+    entries = [
+        {'project': 'x', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['a.go']},
+        {'project': 'x', 'files_changed': ['b.go']},  # most recent: different
+    ]
+    assert is_stuck('x', entries) is False