Add key stepper auto-first-character tests

tests/test_key_stepper.py

@@ -0,0 +1,49 @@
+from types import SimpleNamespace
+
+from ai_typewriter.key_stepper import KeyStepper
+
+
+def test_start_types_first_character_immediately_then_hooks_remaining(monkeypatch):
+    typed = []
+    hooked = []
+
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.write", lambda char, delay=0, exact=True: typed.append(char))
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.hook", lambda callback, suppress=True: hooked.append((callback, suppress)) or "hook")
+
+    stepper = KeyStepper("abc")
+    stepper.start()
+
+    assert typed == ["a"]
+    assert hooked and hooked[0][1] is True
+    assert stepper.remaining_characters == 2
+
+
+def test_single_character_response_does_not_install_hook(monkeypatch):
+    typed = []
+    hooks = []
+
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.write", lambda char, delay=0, exact=True: typed.append(char))
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.hook", lambda callback, suppress=True: hooks.append(callback))
+
+    stepper = KeyStepper("x")
+    stepper.start()
+
+    assert typed == ["x"]
+    assert hooks == []
+    assert stepper.remaining_characters == 0
+
+
+def test_key_down_types_next_character_after_auto_first(monkeypatch):
+    typed = []
+    hook = {}
+
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.write", lambda char, delay=0, exact=True: typed.append(char))
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.hook", lambda callback, suppress=True: hook.setdefault("callback", callback) or "hook")
+    monkeypatch.setattr("ai_typewriter.key_stepper.keyboard.unhook", lambda value: None)
+
+    stepper = KeyStepper("ab")
+    stepper.start()
+    hook["callback"](SimpleNamespace(event_type="down"))
+
+    assert typed == ["a", "b"]
+    assert stepper.remaining_characters == 0