feat: add missing achievement milestones and fix reward types (#188, #189, #190)

- Add quest_hero milestone at 75 quests (closes gap between 50 and 122)
- Add boss_legend milestone at 50 bosses (closes gap between 30 and 72)
- Replace crystal rewards on P50/P100/P150/P200 prestige achievements
  with runestones (100/500/2000/10000) — crystals become worthless by
  the time these are earned, runestones remain meaningful throughout

apps/api/src/data/achievements.ts

@@ -315,6 +315,15 @@ export const defaultAchievements: Array<Achievement> = [
     reward:      { crystals: 5000 },
     unlockedAt:  null,
   },
+  {
+    condition:   { amount: 75, type: "questsCompleted" },
+    description: "Complete 75 quests.",
+    icon:        "🌠",
+    id:          "quest_hero",
+    name:        "Quest Hero",
+    reward:      { crystals: 10_000 },
+    unlockedAt:  null,
+  },
   {
     condition:   { amount: 122, type: "questsCompleted" },
     description: "Complete all 122 quests across the known multiverse.",
@@ -343,6 +352,15 @@ export const defaultAchievements: Array<Achievement> = [
     reward:      { crystals: 5000 },
     unlockedAt:  null,
   },
+  {
+    condition:   { amount: 50, type: "bossesDefeated" },
+    description: "Defeat 50 bosses.",
+    icon:        "⚡",
+    id:          "boss_legend",
+    name:        "Legendary Vanquisher",
+    reward:      { crystals: 15_000 },
+    unlockedAt:  null,
+  },
   {
     condition:   { amount: 72, type: "bossesDefeated" },
     description: "Defeat all 72 bosses across every plane of existence.",
@@ -396,7 +414,7 @@ export const defaultAchievements: Array<Achievement> = [
     icon:        "✨",
     id:          "prestige_transcendent",
     name:        "Transcendent",
-    reward:      { crystals: 10_000 },
+    reward:      { runestones: 100 },
     unlockedAt:  null,
   },
   {
@@ -405,7 +423,7 @@ export const defaultAchievements: Array<Achievement> = [
     icon:        "💎",
     id:          "prestige_eternal",
     name:        "Eternal Looper",
-    reward:      { crystals: 25_000 },
+    reward:      { runestones: 500 },
     unlockedAt:  null,
   },
   {
@@ -414,7 +432,7 @@ export const defaultAchievements: Array<Achievement> = [
     icon:        "🌟",
     id:          "prestige_immortal",
     name:        "Immortal Cycler",
-    reward:      { crystals: 50_000 },
+    reward:      { runestones: 2000 },
     unlockedAt:  null,
   },
   {
@@ -423,7 +441,7 @@ export const defaultAchievements: Array<Achievement> = [
     icon:        "👑",
     id:          "prestige_absolute",
     name:        "Absolute Champion",
-    reward:      { crystals: 100_000 },
+    reward:      { runestones: 10_000 },
     unlockedAt:  null,
   },
 ];