Initial MVP: drivable RX-7 vertical slice + server-authoritative systems

- Rojo + Wally project; ProfileStore (loleris) for safe saves
- Shared: GameConfig, Cars (RX-7 free starter), ProfileTemplate, Remotes
- Server: DataManager, Economy, CarManager, RaceManager, MapBuilder, AntiCheat
- Client: neon HUD + Garage/Dealership UI (buy/equip/upgrade), race/daily
- Procedural Tokyo expressway (spawn pad, finish line, neon pylons, kill walls)
- CI workflow (Gitea/GitHub), Makefile, selene+stylua clean, rojo builds
- Docs: README, GDD, realistic solo ROADMAP

docs/GDD.md

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+# Game Design Document — Fast & Furious: Tokyo Expressway (MVP)
+
+## Vision
+A progression-fantasy street racer. You start in a humble-but-iconic 1993 Mazda
+RX-7 and claw your way up to hypercars on a neon-drenched Tokyo expressway at night.
+Easy to pick up, satisfying to grind, fair to spend on.
+
+## The one-sentence pitch
+"Start in the RX-7, own the expressway."
+
+## Core loop (the addictive 60 seconds)
+1. **Spawn** on the expressway in your equipped car.
+2. **Race** the time-trial down the highway to the finish line.
+3. **Earn** cash + reputation for finishing.
+4. **Spend** in the Garage: upgrade your current car or buy the next tier.
+5. A faster car / better tune makes the next race feel better → back to step 1.
+
+Daily rewards + rising rep gates give a reason to come back tomorrow.
+
+## Pillars
+- **Progression fantasy** — junker → hypercar, always a visible next goal.
+- **Nighttime Tokyo vibe** — neon, speed, style.
+- **Fair monetization** — spending accelerates the grind, never buys wins.
+- **Server-authoritative** — no exploiting money or unlocking cars.
+
+## MVP feature set (what's built)
+- 5-tier car catalogue; **RX-7 is the free starter** (Tier 2).
+- Drivable cars via VehicleSeat (proven, swap-in real mesh later).
+- Procedural expressway map with kill-walls (can't leave the road).
+- Garage + Dealership UI: view / buy / equip / upgrade.
+- Upgrade system: Engine / Tires / Nitro, cost-scaled with diminishing returns.
+- Solo time-trial race with server-validated payouts.
+- Reputation gates on higher-tier cars.
+- Daily login reward.
+- Robust saving via ProfileStore (session-locked, reconciling).
+- Basic movement anti-cheat.
+
+## Deliberately deferred (see ROADMAP)
+Traffic AI, head-to-head/drag racing, car customization cosmetics, crews/PvP,
+full city map, mobile-tuned optimization pass, monetization products.
+
+## Economy first-pass numbers (tune freely in `GameConfig`)
+- Start: $1,500, 0 rep, own the RX-7.
+- Race finish: +$650 (base+win) and +15 rep.
+- Daily: +$300, +10 rep.
+- Upgrades: base $500, ×1.6 per level, cap level 5 per part.
+- Car tiers: Junk $800 → S15 $12k (50 rep) → R34 $45k (180 rep) → Hyper $250k (600 rep).
+
+## Win condition / retention
+No hard "end" — the chase up the tiers plus daily rewards and (future) leaderboards
+supply the long tail. First-session goal: earn enough to feel one upgrade land
+inside the first 10 minutes.