Character and movement pass

NPC characters
- Articulated rig (hips/knees, shoulders/elbows/hands) replaces rigid capsules;
  the walk cycle bends knees and elbows and flees with a longer stride.
- Layered outfits (jacket/vest/coat/dress), extended accessories and hand items
  (bag, umbrella, phone, camera, clipboard, cup), face details and five hair
  silhouettes, all deterministic per profile seed.
- Idle behaviour layers (phone, clipboard, crossed arms, look-around), breathing
  and weight shift; escalation raises hands or points, and noticed NPCs turn
  toward the guard.
- Reaction symbols above the head (!!, ?!, !, ?), door-queue offsets assigned by
  GameManager, three LOD tiers with hysteresis and a billboard impostor.
- smoke_npc_budget.gd: 16 avatars = 534 meshes, ~6.9 ms average (50 ms budget).

Player movement
- Separate accel/decel, step-up assist for kerbs and the entrance steps, and a
  forward-axis fix: W was inverted (get_axis(forward, back) is negative).
- Head bob, landing dip and precision-walk FOV, gated by persisted head-bob and
  invert-Y settings; precision chip and tick; surface-aware footsteps and a
  landing cue forwarded to AudioFeedback.
- Gamepad support (sticks, deadzone, face buttons, bumpers), a control legend
  that follows the active device, and named actions for the remaining keys.
- Key/button remapping in Settings, persisted as input_bindings and applied by
  InputBindings (mouse and gamepad axes are never removed).
- smoke_movement.gd (windowed): climbs the steps, checks precision speed, chip,
  footsteps and landing; new 11-precision-walk capture and catalogue entry.

Verification: headless 208/208, Python tooling 56/56, all 11 smokes pass,
compare 11 good / 0 bad, movement judge match. Version 0.5.0. Only optional
Future ideas remain in TODO.

src/test/tests/test_input_bindings.gd

@@ -0,0 +1,53 @@
+extends RefCounted
+## Headless tests for the key/button remap helper.
+
+const InputBindings := preload("res://src/core/input_bindings.gd")
+
+func test_descriptor_from_events() -> bool:
+	var key := InputEventKey.new()
+	key.physical_keycode = KEY_Z
+	var a := TestUtils.check_eq(InputBindings.descriptor_from_event(key),
+		{"type": "key", "code": int(KEY_Z)}, "keys store a code")
+	var button := InputEventJoypadButton.new()
+	button.button_index = JOY_BUTTON_Y
+	var b := TestUtils.check_eq(InputBindings.descriptor_from_event(button),
+		{"type": "joy", "button": int(JOY_BUTTON_Y)}, "pad buttons store an index")
+	var c := TestUtils.check(
+		InputBindings.descriptor_from_event(InputEventMouseButton.new()).is_empty(),
+		"mouse buttons are not remappable")
+	return a and b and c
+
+func test_apply_rebinds_and_keeps_mouse_events() -> bool:
+	var old := InputBindings.current_descriptor("inspect")
+	var remap := {"inspect": {"type": "key", "code": int(KEY_Z)}}
+	InputBindings.apply(remap)
+	var rebound := InputBindings.current_descriptor("inspect")
+	var a := TestUtils.check_eq(rebound, {"type": "key", "code": int(KEY_Z)},
+		"inspect now uses the new key")
+	var action_menu_mouse := 0
+	for event in InputMap.action_get_events("action_menu"):
+		if event is InputEventMouseButton:
+			action_menu_mouse += 1
+	var b := TestUtils.check(action_menu_mouse > 0,
+		"remapping leaves mouse events alone")
+	# Restore the original binding for later tests.
+	if not old.is_empty():
+		InputBindings.apply({"inspect": old})
+	return a and b
+
+func test_apply_accepts_pad_buttons() -> bool:
+	var remap := {"wand": {"type": "joy", "button": int(JOY_BUTTON_RIGHT_SHOULDER)}}
+	InputBindings.apply(remap)
+	var a := TestUtils.check_eq(InputBindings.current_descriptor("wand"),
+		{"type": "joy", "button": int(JOY_BUTTON_RIGHT_SHOULDER)},
+		"actions can be rebound to a pad button")
+	InputBindings.apply({"wand": {"type": "key", "code": int(KEY_C)}})
+	return a
+
+func test_labels_are_human_readable() -> bool:
+	var a := TestUtils.check(InputBindings.label_for(
+		{"type": "key", "code": int(KEY_W)}) == "W", "key label")
+	var b := TestUtils.check(InputBindings.label_for(
+		{"type": "joy", "button": 3}) == "Pad 3", "pad label")
+	var c := TestUtils.check_eq(InputBindings.label_for({}), "", "empty label")
+	return a and b and c