test(room-navigator): add missing is_at_home and go_to_hospital tests

Adds 7 new test cases covering home/hospital navigation state:
- is_at_home() initial state and transitions
- go_to_home() with idempotence check
- go_to_hospital() state restoration and guards
- is_at_home flag cleanup on room navigation

Implements corresponding methods in RoomNavigator:
- is_at_home(): Returns home state
- go_to_home(): Navigates to home (0,0) and saves hospital position
- go_to_hospital(): Returns to previously saved hospital location
- _go_to_room_internal(): Helper to avoid flag interference

All 34 tests passing.

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

test/unit/test_room_navigator.gd

@@ -89,3 +89,52 @@ func test_multiple_room_changes_update_state() -> void:
 	_nav.go_to_room(2, 3)
 	assert_eq(_nav.get_current_floor(), 2)
 	assert_eq(_nav.get_current_room(), 3)
+
+
+func test_is_at_home_starts_false() -> void:
+	assert_false(_nav.is_at_home())
+
+
+func test_go_to_home_sets_is_at_home_true() -> void:
+	_nav.go_to_home()
+	assert_true(_nav.is_at_home())
+
+
+func test_go_to_home_twice_is_noop_on_second_call() -> void:
+	_nav.go_to_home()
+	var camera_pos: Vector2 = _camera.position
+	_nav.go_to_home()
+	assert_eq(_camera.position, camera_pos)
+
+
+func test_go_to_hospital_clears_is_at_home() -> void:
+	_nav.go_to_home()
+	_nav.go_to_hospital()
+	assert_false(_nav.is_at_home())
+
+
+func test_go_to_hospital_restores_last_floor() -> void:
+	_nav.go_to_room(1, 2)
+	_nav.go_to_home()
+	_nav.go_to_hospital()
+	assert_eq(_nav.get_current_floor(), 1)
+
+
+func test_go_to_hospital_restores_last_room() -> void:
+	_nav.go_to_room(1, 2)
+	_nav.go_to_home()
+	_nav.go_to_hospital()
+	assert_eq(_nav.get_current_room(), 2)
+
+
+func test_go_to_hospital_when_not_at_home_is_noop() -> void:
+	_nav.go_to_room(1, 2)
+	var camera_pos: Vector2 = _camera.position
+	_nav.go_to_hospital()
+	assert_eq(_camera.position, camera_pos)
+
+
+func test_go_to_room_after_home_clears_is_at_home() -> void:
+	_nav.go_to_home()
+	_nav.go_to_room(0, 0)
+	assert_false(_nav.is_at_home())