Scope cut: drive-only MVP (remove racing + economy)

Per user direction, the MVP is now simply driving cars on the expressway.
- Removed RaceManager and Economy modules entirely
- Slimmed Remotes to DataUpdated / SpawnCar / EquipCar
- ProfileTemplate now just remembers the last driven car (v2)
- Cars: dropped price/rep/upgrade fields; kept identity + driving stats
- CarManager: stat-based tuning only; RX-7 allowlist via GameConfig.canDrive
- DataManager: assign default car on join; downgrade RX-7 if de-allowlisted
- Client: replaced garage/economy UI with a simple car picker + respawn
- Docs: GDD/ROADMAP/README rewritten for drive-only; added docs/MESH_SWAP.md
- Gates: stylua clean, selene 0/0, rojo builds

src/server/CarManager.luau

@@ -9,8 +9,6 @@
 	the most reliable, least-buggy way to get a car moving on day one. When you
 	later import the real RX-7 mesh + a constraint chassis (A-Chassis style),
 	you swap out `buildCarModel` and keep everything else.
-
-	Upgrades scale MaxSpeed / Torque / TurnSpeed so the upgrade economy is real.
 ]]
 
 local Players = game:GetService("Players")
@@ -20,10 +18,8 @@ local ReplicatedStorage = game:GetService("ReplicatedStorage")
 local Shared = ReplicatedStorage.Shared
 local Cars = require(Shared.Cars)
 local GameConfig = require(Shared.GameConfig)
-local ProfileTemplate = require(Shared.ProfileTemplate)
 local DataManager = require(script.Parent.DataManager)
 
-type ProfileData = ProfileTemplate.ProfileData
 type Car = Cars.Car
 
 local CarManager = {}
@@ -31,17 +27,11 @@ local CarManager = {}
 local activeCars: { [Player]: Model } = {}
 local carsFolder: Folder
 
--- Convert a car's 0-100 stats + upgrade levels into VehicleSeat tuning --------
-local function computeTuning(car: Car, upgrades: { Engine: number, Tires: number, Nitro: number })
-	local engineLvl = upgrades.Engine or 0
-	local tiresLvl = upgrades.Tires or 0
-	-- Base values derived from stats; upgrades add a percentage on top.
+-- Convert a car's 0-100 stats into VehicleSeat tuning ------------------------
+local function computeTuning(car: Car)
 	local maxSpeed = 60 + car.Stats.Speed * 1.6 -- studs/sec-ish target
-	maxSpeed *= (1 + engineLvl * 0.08) -- +8% top speed per engine level
 	local torque = 8000 + car.Stats.Acceleration * 220
-	torque *= (1 + engineLvl * 0.10)
 	local turnSpeed = 20 + car.Stats.Handling * 0.35
-	turnSpeed *= (1 + tiresLvl * 0.06) -- tires help turn-in
 	return maxSpeed, torque, turnSpeed
 end
 
@@ -126,26 +116,14 @@ function CarManager.spawn(player: Player, carId: string?)
 	if not car then
 		return
 	end
-	-- Defense in depth: never spawn the restricted RX-7 for a non-allowlisted user,
-	-- even if their save somehow contained it.
-	if car.Id == GameConfig.RestrictedStarterCarId and not GameConfig.isRX7Allowed(player.UserId) then
-		return
-	end
-	-- Only spawn cars the player owns (anti-cheat: no spawning unowned exotics).
-	local owned
-	for _, o in ipairs(data.OwnedCars) do
-		if o.Id == id then
-			owned = o
-			break
-		end
-	end
-	if not owned then
+	-- Restricted car (RX-7) can only be driven by allowlisted UserIds.
+	if not GameConfig.canDrive(player.UserId, car.Id, car.Restricted) then
 		return
 	end
 
 	CarManager.despawn(player)
 
-	local maxSpeed, torque, turnSpeed = computeTuning(car, owned.Upgrades)
+	local maxSpeed, torque, turnSpeed = computeTuning(car)
 	local model = buildCarModel(car, maxSpeed, torque, turnSpeed)
 	model:PivotTo(spawnCFrame())
 	model.Parent = carsFolder