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]>

scenes/maps/level_environment.gd

@@ -33,6 +33,20 @@ static func add_to(level: Node, sky_variant: String = "day") -> WorldEnvironment
 		fill.light_energy = 0.25
 		fill.shadow_enabled = false
 		level.add_child(fill)
+
+	# Quiet ambient bed so the arena never sits in dead air.
+	if not level.has_node("AmbientBed") and ResourceLoader.exists("res://assets/sounds/wind.wav"):
+		var amb := AudioStreamPlayer.new()
+		amb.name = "AmbientBed"
+		amb.stream = load("res://assets/sounds/wind.wav")
+		if amb.stream is AudioStreamWAV:
+			amb.stream.loop_mode = AudioStreamWAV.LOOP_FORWARD
+			amb.stream.loop_end = amb.stream.data.size() / 2
+		amb.volume_db = -30.0
+		amb.pitch_scale = 0.6
+		amb.bus = "SFX"
+		amb.autoplay = true
+		level.add_child(amb)
 	return env
 
 

scenes/maps/level_materials.gd

@@ -42,6 +42,11 @@ static func tinted(tint: Color, dark: bool = false) -> Material:
 	# land near the original flat color while keeping the grid contrast.
 	mat.set_shader_parameter("albedo_color", Color(
 		minf(tint.r * 1.9, 1.0), minf(tint.g * 1.9, 1.0), minf(tint.b * 1.9, 1.0)))
+	# Level surfaces are huge; the toon rim/specular reads as a giant soft
+	# "blob" highlight smeared across floors and walls. Keep those effects
+	# for characters/props only.
+	mat.set_shader_parameter("rim_strength", 0.0)
+	mat.set_shader_parameter("specular_strength", 0.0)
 	_cache[key] = mat
 	return mat
 

scenes/maps/level_runtime.gd

@@ -18,7 +18,12 @@ var _debug_ui_panel: PanelContainer
 func _ready() -> void:
 	# Hide mouse
 	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED
-	
+
+	# Maps that don't ship their own environment get the shared stylized one
+	# (sky gradient, sun+fill, glow, cel color grade, ambient bed).
+	if not has_node("WorldEnvironment"):
+		LevelEnvironment.add_to(self)
+
 	_build_hud()
 	
 	# Multiplayer Spawning