fix: Golemancy enchantment capacity, design persistence, and UI selectors

- Fix enchantment capacity formula: multiply magicAffinity by 100 (spec treats it as percentage)
- Fix enterSpireMode preserving golemDesigns (only reset loadout/activeGolems per spec §9)
- Add mana type selector UI for Intermediate/Advanced/Guardian cores
- Add spell selector UI for circuits with spell slots

Fixes #310, #311, #312

src/lib/game/data/golems/golemancy-data.test.ts

@@ -136,7 +136,7 @@ describe('Computed stats', () => {
     expect(stats.magicAffinity).toBe(0.3);
     expect(stats.aoeTargets).toBe(1);
     expect(stats.spellSlots).toBe(0);
-    expect(stats.enchantmentCapacity).toBeCloseTo(0.3);
+    expect(stats.enchantmentCapacity).toBeCloseTo(30); // Earth Frame 30% × Basic Core 1.0
     expect(stats.specialEffect).toBe('none');
     expect(stats.availableManaTypes).toEqual(['earth']);
   });
@@ -153,7 +153,7 @@ describe('Computed stats', () => {
     expect(stats.armorPierce).toBe(0.5);
     expect(stats.magicAffinity).toBe(0.5);
     expect(stats.spellSlots).toBe(2);
-    expect(stats.enchantmentCapacity).toBeCloseTo(1.0);
+    expect(stats.enchantmentCapacity).toBeCloseTo(100); // Steel Frame 50% × Advanced Core 2.0
   });
 
   it('guardian crystalSteelHybrid golem with guardian circuit', () => {
@@ -168,7 +168,7 @@ describe('Computed stats', () => {
     expect(stats.armorPierce).toBe(0.7);
     expect(stats.magicAffinity).toBe(1.0);
     expect(stats.spellSlots).toBe(4);
-    expect(stats.enchantmentCapacity).toBeCloseTo(3.0);
+    expect(stats.enchantmentCapacity).toBeCloseTo(300); // Crystal-Steel Hybrid 100% × Guardian Core 3.0
     expect(stats.specialEffect).toBe('guardianConstruct');
   });
 

src/lib/game/data/golems/utils.ts

@@ -90,8 +90,9 @@ export function computeGolemStats(design: GolemDesign): ComputedGolemStats {
     },
   ];
 
-  // Enchantment capacity = Frame.MagicAffinity × Core.TierMultiplier
-  const enchantmentCapacity = frame.magicAffinity * core.tierMultiplier;
+  // Enchantment capacity = Frame.MagicAffinity(%) × Core.TierMultiplier
+  // magicAffinity is stored as decimal (0.3 = 30%) per spec §5.1, so multiply by 100
+  const enchantmentCapacity = Math.round(frame.magicAffinity * 100) * core.tierMultiplier;
 
   return {
     maxRoomDuration: core.maxRoomDuration,

src/lib/game/stores/combat-descent-actions.ts

@@ -253,7 +253,7 @@ export function createEnterSpireMode(get: GetFn, set: SetFn) {
       roomResetState: {},
       descentPeak: null,
       isDescentComplete: false,
-      golemancy: { activeGolems: [], lastSummonFloor: 0, golemDesigns: {}, golemLoadout: [] },
+      golemancy: { activeGolems: [], lastSummonFloor: 0, golemDesigns: s.golemancy?.golemDesigns ?? {}, golemLoadout: [] },
     });
 
     get().addActivityLog('floor_transition',