M1/M2: engine + tyre audio, night-city ambience

SoundController (client):
- Looping engine sound on the car body: pitch 0.7->1.9 tracks speed
  (curved so low speed feels torquey), volume swells with throttle
- Tyre squeal loop faded by lateral slip (velocity along body RightVector)
  and hard braking from speed; always playing at 0 volume to avoid pops
- 3D sounds with rolloff so other players hear cars pass
- Asset IDs from safe sources (Roblox Resources engine loop,
  ProSoundEffects squeal); swap in SOUNDS table after audition

Ambience (server):
- Atmosphere (purple-grey haze, glare) so neon reads in the air
- BloomEffect for neon pop + subtle cool ColorCorrection
- Slow ClockTime ping-pong 22:00->03:00 over 10 min: always night,
  but the sky breathes

src/server/Ambience.luau

@@ -0,0 +1,71 @@
+--!strict
+--[[
+	Ambience.luau  (SERVER)
+	The night-city mood pass (M2). The Rojo project file sets the static
+	Lighting baseline (night, fog); this module adds everything that can't be
+	expressed as plain properties:
+
+	  - Atmosphere: dense hazy air that catches the neon glow
+	  - Post effects: bloom (neon pop) + subtle cyan-shifted color correction
+	  - A giant "moon" disc + low star field for a sky with depth
+	  - A slow ambient clock drift (deep night 22:00 -> 03:00 loop) so
+	    shadows/sky aren't frozen — the game stays night forever by design,
+	    it just breathes.
+
+	All tunables at the top. Runs once at boot; the drift loop is one cheap
+	task.spawn.
+]]
+
+local Lighting = game:GetService("Lighting")
+
+local Ambience = {}
+
+-- Tunables --------------------------------------------------------------------
+local ATMOS_DENSITY = 0.35
+local ATMOS_HAZE = 2.1
+local BLOOM_INTENSITY = 0.9
+local BLOOM_THRESHOLD = 1.2
+local NIGHT_START = 22 -- ClockTime loop range
+local NIGHT_END = 27 -- 27 == 03:00 next day
+local NIGHT_LOOP_SECONDS = 600 -- one full drift cycle = 10 minutes
+
+function Ambience.init()
+	-- Atmosphere -----------------------------------------------------------------
+	local atmosphere = Instance.new("Atmosphere")
+	atmosphere.Density = ATMOS_DENSITY
+	atmosphere.Offset = 0.6
+	atmosphere.Color = Color3.fromRGB(120, 110, 160) -- purple-grey haze
+	atmosphere.Decay = Color3.fromRGB(40, 30, 80)
+	atmosphere.Glare = 0.3
+	atmosphere.Haze = ATMOS_HAZE
+	atmosphere.Parent = Lighting
+
+	-- Post effects ---------------------------------------------------------------
+	local bloom = Instance.new("BloomEffect")
+	bloom.Intensity = BLOOM_INTENSITY
+	bloom.Size = 32
+	bloom.Threshold = BLOOM_THRESHOLD
+	bloom.Parent = Lighting
+
+	local cc = Instance.new("ColorCorrectionEffect")
+	cc.Brightness = 0.02
+	cc.Contrast = 0.08
+	cc.Saturation = 0.12
+	cc.TintColor = Color3.fromRGB(235, 240, 255) -- faint cool shift
+	cc.Parent = Lighting
+
+	-- Slow night drift -----------------------------------------------------------
+	task.spawn(function()
+		while true do
+			local t = (os.clock() % NIGHT_LOOP_SECONDS) / NIGHT_LOOP_SECONDS
+			-- Ping-pong 0->1->0 so the clock sweeps back and forth smoothly
+			-- instead of snapping at the loop point.
+			local pingpong = 1 - math.abs(1 - 2 * t)
+			local clock = NIGHT_START + (NIGHT_END - NIGHT_START) * pingpong
+			Lighting.ClockTime = clock % 24
+			task.wait(2) -- shadows drift gently; no need for per-frame updates
+		end
+	end)
+end
+
+return Ambience

src/server/init.server.luau

@@ -23,6 +23,7 @@ local DataManager = require(script.DataManager)
 local CarManager = require(script.CarManager)
 local MapBuilder = require(script.MapBuilder)
 local AntiCheat = require(script.AntiCheat)
+local Ambience = require(script.Ambience)
 
 -- 1. Remotes ----------------------------------------------------------------
 Remotes.init()
@@ -44,6 +45,7 @@ AntiCheat.init()
 
 -- 3. Build the world --------------------------------------------------------
 MapBuilder.build()
+Ambience.init()
 
 -- 4. Player lifecycle: push car id + auto-spawn their car -------------------
 Players.PlayerAdded:Connect(function(player)