feat: add equipment, achievements, and visual polish

- Equipment system: 12 items across weapon/armour/trinket slots with
  common/rare/epic/legendary rarities; starter commons auto-equipped,
  higher tiers drop from boss victories
- Achievement system: 15 milestones with typed conditions; checked
  each tick and crystal rewards applied automatically
- Achievement toast: slide-in notification, auto-dismisses after 4s
- Floating click text: +X gold floats on each manual click
- Expanded quests (9 total) and upgrades (12 total)
- Upgrade panel now shows locked upgrades so players can see their
  progression path
- formatNumber utility (K/M/B/T) used consistently across all panels
- Backfill logic for existing saves to add new content gracefully
- types package now emits .d.ts declarations

apps/api/src/data/adventurers.ts

@@ -8,6 +8,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 1,
     goldPerSecond: 0.1,
     essencePerSecond: 0,
+    combatPower: 1,
     count: 0,
     unlocked: true,
   },
@@ -18,6 +19,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 2,
     goldPerSecond: 0.5,
     essencePerSecond: 0,
+    combatPower: 3,
     count: 0,
     unlocked: false,
   },
@@ -28,6 +30,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 3,
     goldPerSecond: 1.5,
     essencePerSecond: 0.01,
+    combatPower: 8,
     count: 0,
     unlocked: false,
   },
@@ -38,6 +41,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 4,
     goldPerSecond: 4,
     essencePerSecond: 0.02,
+    combatPower: 20,
     count: 0,
     unlocked: false,
   },
@@ -48,6 +52,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 5,
     goldPerSecond: 10,
     essencePerSecond: 0.05,
+    combatPower: 50,
     count: 0,
     unlocked: false,
   },
@@ -58,6 +63,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 6,
     goldPerSecond: 25,
     essencePerSecond: 0.1,
+    combatPower: 120,
     count: 0,
     unlocked: false,
   },
@@ -68,6 +74,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 7,
     goldPerSecond: 75,
     essencePerSecond: 0.2,
+    combatPower: 300,
     count: 0,
     unlocked: false,
   },
@@ -78,6 +85,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 8,
     goldPerSecond: 200,
     essencePerSecond: 0.5,
+    combatPower: 800,
     count: 0,
     unlocked: false,
   },
@@ -88,6 +96,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 9,
     goldPerSecond: 600,
     essencePerSecond: 1,
+    combatPower: 2000,
     count: 0,
     unlocked: false,
   },
@@ -98,6 +107,7 @@ export const DEFAULT_ADVENTURERS: Adventurer[] = [
     level: 10,
     goldPerSecond: 2000,
     essencePerSecond: 3,
+    combatPower: 6000,
     count: 0,
     unlocked: false,
   },