tweak: reduce Mini Motorways difficulty and slow pacing

- Increase week duration (55s → 70s) and delay color unlocks
- Lower house/building caps (30→20, 12→8) and slow car speed (3.0→2.5)
- Increase house/building spawn intervals and slow pin accumulation
- Start with 1 color instead of 2 for a gentler learning curve

public/src/games/minimotorways/MiniMotorwaysLogic.js

@@ -14,17 +14,17 @@ export const COLOR_HEX = {
 };
 
 export const TUNE = {
-  WEEK_MS: 55000,
+  WEEK_MS: 70000,
   SUBSTEP_MS: 50,
   CAR_CAP: 60,
-  HOUSE_CAP: 30,
-  BUILDING_CAP: 12,
-  CAR_SPEED: 3.0,              // cells / second
+  HOUSE_CAP: 20,
+  BUILDING_CAP: 8,
+  CAR_SPEED: 2.5,              // cells / second
   HEADWAY: 0.65,               // minimum gap behind the car ahead, in cells
   DWELL_MS: 1000,
   COOLDOWN_MS: 2000,
-  PIN_MS_BASE: 12500,          // pin interval = max(MIN, BASE * DECAY^week)
-  PIN_MS_DECAY: 0.96,
+  PIN_MS_BASE: 18000,          // pin interval = max(MIN, BASE * DECAY^week)
+  PIN_MS_DECAY: 0.94,
   PIN_MS_MIN: 3500,
   PIN_GRACE_MS: 15000,         // new buildings wait this long before pin #1
   PIN_CAP: 12,
@@ -32,12 +32,12 @@ export const TUNE = {
   OVERFLOW_MS: 35000,          // full ring → game over
   OVERFLOW_DRAIN: 2,           // ring drains at 2x fill rate while pins < 8
   DELIVERY_RELIEF: 0.06,       // each delivery knocks the ring down a touch
-  HOUSE_MS_BASE: 9000,
-  HOUSE_MS_DECAY: 0.95,
-  HOUSE_MS_MIN: 5000,
-  BUILDING_MS_BASE: 85000,
-  BUILDING_MS_DECAY: 0.93,
-  BUILDING_MS_MIN: 50000,
+  HOUSE_MS_BASE: 25000,
+  HOUSE_MS_DECAY: 0.85,
+  HOUSE_MS_MIN: 12000,
+  BUILDING_MS_BASE: 120000,
+  BUILDING_MS_DECAY: 0.88,
+  BUILDING_MS_MIN: 70000,
   START_ROADS: 30,
   WEEK_ROADS: 12,
   UPGRADE_ROADS: 10,
@@ -49,7 +49,7 @@ export const TUNE = {
   ROUNDABOUT_CAP: 2,
   DISPATCH_MS: 500,
   SECOND_CAR_WEEK: 2,          // houses gain a second car from this week on
-  COLOR_UNLOCK_WEEKS: [0, 0, 2, 4, 7, 10],
+  COLOR_UNLOCK_WEEKS: [0, 0, 3, 5, 8, 11],
   GROWTH: [
     { week: 0, w: 20, h: 12 },
     { week: 3, w: 26, h: 16 },
@@ -312,8 +312,8 @@ export class Sim {
     this.houseT = this.houseInterval();
     this.buildingT = this.buildingInterval();
 
-    // Week 0 opens with two colours, each seeded with a destination and homes.
-    this.unlockColors(2);
+    // Week 0 opens with one colour, each seeded with a destination and homes.
+    this.unlockColors(1);
   }
 
   // ── Small helpers ────────────────────────────────────────────────────────────