feat: cel-shaded look & feel overhaul — real audio, comic UI, themed VFX

Audio (all CC0 — Kenney packs + OpenGameArt, see assets/sounds/SOURCES.md):
- Replace every procedural synth WAV with forged sounds (ffmpeg pitch/layer
  mixes): distinct fire sounds per weapon with 2-3 variations, explosions,
  footsteps x5, land/jump/dash/vault, knife swing, hit/kill confirms,
  bullet impacts, reload, flight loops, UI hover/click/confirm/error,
  match jingles, menu music
- AudioManager.stream_for(): AudioStreamRandomizer per sound id — every
  weapon now gets variation + pitch randomization on each shot
- Explosions and bullet impacts play positional audio; landing has its own
  sound instead of a pitched footstep; ambient wind bed on every map

Visuals:
- ExplosionVFX: shared cel-shaded burst (white-hot stepped core, ink
  shockwave ring, star spikes, flat smoke puffs) replaces the orange
  sphere in both local and remote-replay paths
- Comic star muzzle flashes on all weapons; unified cel tracer bolts with
  ink outlines across hitscan/shotgun/remote paths
- Impact decals: hard-stepped ink-splat gradients instead of soft airbrush
- Toon shading on first-person view models + arms, third-person weapons,
  and the procedural humanoid fallback (no hull outlines on FBX weapons —
  their hard normals tear the inverted hull)
- Fix: giant soft "blob" highlight on floors — toon rim/specular disabled
  on level-geometry materials (pre-existing artifact since the cel commit)
- Fix: own third-person weapon rendered into the first-person camera
  (shadows-only now covers first_person_mode)

UI:
- UITheme: comic theme on the root window — Bangers display font (OFL),
  paper panels with thick ink borders + hard drop shadows, papaya accent,
  themed buttons/inputs/popups; hover/click sounds on all menu buttons
- Main menu: tilted comic wordmark, sunset toon diorama, looping menu music
- Match HUD: themed scoreboard/killfeed/kill counter

Viewports:
- 4x MSAA project-wide + viewmodel/diorama viewports (crisp ink lines)
- Viewmodel camera near plane 0.01; third-person camera FOV syncs settings
- debug/visual_capture.gd: dev tool to screenshot menu + level for review

Verified: 11/11 movement tests, spawn smoke test 0 failures, before/after
screenshot comparison of menu and level.

Co-Authored-By: Claude Fable 5 <[email protected]>

ui/main_menu/main_menu.gd

@@ -9,7 +9,23 @@ var _host_lobby_players_list: ItemList
 
 func _ready() -> void:
 	Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)
-	
+
+	# Comic/cel theme for every Control in the game (root window inherits down)
+	UITheme.apply_global(get_tree())
+
+	# Menu music (scene-owned: stops automatically when a level loads)
+	var music_path := "res://assets/sounds/music_menu.wav"
+	if ResourceLoader.exists(music_path):
+		var music := AudioStreamPlayer.new()
+		music.stream = load(music_path)
+		if music.stream is AudioStreamWAV:
+			music.stream.loop_mode = AudioStreamWAV.LOOP_FORWARD
+			music.stream.loop_end = music.stream.data.size() / 4  # 16-bit stereo frames
+		music.bus = "Music"
+		music.volume_db = -8.0
+		music.autoplay = true
+		add_child(music)
+
 	var nm = get_node_or_null("/root/NetworkManager")
 	if nm:
 		nm.connection_succeeded.connect(_on_connection_succeeded)
@@ -25,6 +41,7 @@ func _ready() -> void:
 	
 	var viewport = SubViewport.new()
 	viewport.own_world_3d = true
+	viewport.msaa_3d = Viewport.MSAA_4X
 	right_panel.add_child(viewport)
 	
 	_build_3d_diorama(viewport)
@@ -40,13 +57,14 @@ func _ready() -> void:
 	_ui_vbox.set_anchor_and_offset(SIDE_BOTTOM, 1.0, -50)
 	add_child(_ui_vbox)
 
-	# Title
+	# Title — big comic wordmark with a slight kinetic tilt
 	var title = Label.new()
-	title.text = "Papaya Shooter"
-	title.add_theme_font_size_override("font_size", 72)
-	title.add_theme_color_override("font_color", Color(1, 0.6, 0.2)) # Papaya orange
-	title.add_theme_color_override("font_outline_color", Color(0, 0, 0))
-	title.add_theme_constant_override("outline_size", 12)
+	title.text = "PAPAYA SHOOTER"
+	title.add_theme_font_size_override("font_size", 92)
+	title.add_theme_color_override("font_color", UITheme.PAPAYA)
+	title.add_theme_color_override("font_outline_color", UITheme.INK)
+	title.add_theme_constant_override("outline_size", 16)
+	title.rotation_degrees = -2.5
 	_ui_vbox.add_child(title)
 	
 	# Spacer
@@ -269,6 +287,9 @@ func _ready() -> void:
 	_host_lobby_players_list.add_theme_font_size_override("font_size", 24)
 	hl_right.add_child(_host_lobby_players_list)
 
+	# Hover/click sounds on every menu button
+	UITheme.wire_sounds(self)
+
 func _load_maps_modularly(target_hbox: Container, is_multiplayer: bool, card_size: Vector2) -> void:
 	var maps_dir = "res://scenes/maps/"
 	var dir = DirAccess.open(maps_dir)
@@ -492,13 +513,9 @@ func _build_3d_diorama(viewport: SubViewport) -> void:
 	var world = Node3D.new()
 	viewport.add_child(world)
 	
-	# Lighting and Env
+	# Lighting and Env — same stylized sunset sky as in-game for continuity
 	var env = WorldEnvironment.new()
-	var environment = Environment.new()
-	environment.background_mode = Environment.BG_COLOR
-	environment.background_color = Color(0.1, 0.15, 0.2) # Dark stylish background
-	environment.tonemap_mode = Environment.TONE_MAPPER_ACES
-	env.environment = environment
+	env.environment = LevelEnvironment.make_environment("sunset")
 	world.add_child(env)
 	
 	var sun = DirectionalLight3D.new()
@@ -514,22 +531,21 @@ func _build_3d_diorama(viewport: SubViewport) -> void:
 	fill.light_energy = 0.5
 	world.add_child(fill)
 	
-	# Floor
+	# Floor — toon world-grid like the levels
 	var floor_mesh = MeshInstance3D.new()
 	floor_mesh.mesh = PlaneMesh.new()
 	floor_mesh.mesh.size = Vector2(20, 20)
-	var floor_mat = StandardMaterial3D.new()
-	floor_mat.albedo_color = Color(0.2, 0.2, 0.2)
-	floor_mesh.mesh.surface_set_material(0, floor_mat)
+	floor_mesh.mesh.surface_set_material(0, LevelMaterials.tinted(Color(0.32, 0.3, 0.38)))
 	world.add_child(floor_mesh)
-	
+
 	# Player Model (Sliding Pose)
 	var player_model = Node3D.new()
 	player_model.position = Vector3(0, 0.5, 0) # Lowered for slide
 	world.add_child(player_model)
-	
+
 	var body_mat = StandardMaterial3D.new()
 	body_mat.albedo_color = Color(0.3, 0.6, 0.9)
+	# Toonified below via apply_toon_recursive once the model is assembled
 	
 	# Torso (Capsule tilted back)
 	var torso = MeshInstance3D.new()
@@ -576,6 +592,9 @@ func _build_3d_diorama(viewport: SubViewport) -> void:
 		if shotgun.has_method("set_process_input"):
 			shotgun.set_process_input(false)
 	
+	# Cel-shade the diorama (no hull outlines — the FBX shotgun tears them)
+	LevelMaterials.apply_toon_recursive(player_model, 0.0)
+
 	# Camera
 	var camera = Camera3D.new()
 	world.add_child(camera)