Ship the 0.9.0 production-quality milestone

Add mixer/accessibility settings, caption/reduce-motion hooks, audio volume
clamping, a 24-NPC performance smoke and shortened coat/dress stride for hem
clipping. Record the explicit Godot 4.3-CI/4.7-local matrix and the 0.9
production scope. Headless 250/250, Python 94/94, 24-NPC budget smoke passes.

src/test/tests/test_audio_feedback.gd

@@ -66,6 +66,18 @@ func test_radio_crackle_methods() -> bool:
 	audio.free()
 	return a and b
 
+func test_volume_settings_are_stored_and_applied() -> bool:
+	var audio: Node = AudioFeedback.new()
+	audio.set_volumes(0.8, 0.5, 0.2)
+	var a := TestUtils.check(is_equal_approx(audio.master_volume, 0.8), "master volume stores")
+	var b := TestUtils.check(is_equal_approx(audio.sfx_volume, 0.5), "sfx volume stores")
+	var c := TestUtils.check(is_equal_approx(audio.ambience_volume, 0.2), "ambience volume stores")
+	audio.set_volumes(3.0, -1.0, 0.5)
+	var d := TestUtils.check(is_equal_approx(audio.master_volume, 1.0)
+		and is_equal_approx(audio.sfx_volume, 0.0), "volumes clamp")
+	audio.free()
+	return a and b and c and d
+
 func test_game_manager_wires_audio() -> bool:
 	var src := FileAccess.get_file_as_string("res://src/game/game_manager.gd")
 	var a := TestUtils.check(src.contains("audio.start_crowd_bed()"), "the bed starts with the shift")