fix: clone nested element objects in discipline-slice processTick to avoid bypassing Zustand reactivity

docs/circular-deps.txt

@@ -1,8 +1,8 @@
 # Circular Dependencies
-Generated: 2026-05-19T10:06:50.403Z
+Generated: 2026-05-19T10:35:03.017Z
 Found: 3 circular chain(s) — these MUST be fixed before modifying involved files.
 
-1. Processed 121 files (1.3s) (28 warnings)
+1. Processed 121 files (1.2s) (4 warnings)
 2. 1) data/equipment/index.ts > data/equipment/utils.ts
 3. 2) data/golems/index.ts > data/golems/utils.ts
 

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-05-19T10:06:48.891Z",
+    "generated": "2026-05-19T10:35:01.630Z",
     "description": "Import dependency graph for src/lib/game. Keys are files, values are arrays of files they import.",
     "usage": "To find what a file affects, search for its path in the VALUES. To find what a file depends on, look at its KEY entry."
   },

src/lib/game/stores/discipline-slice.ts

@@ -101,8 +101,11 @@ export const useDisciplineStore = create<DisciplineStore>()(
 
           if (def.manaType === 'raw') {
             rawMana -= drain;
-          } else {
-            elements[def.manaType].current -= drain;
+          } else if (elements[def.manaType]) {
+            elements[def.manaType] = {
+              ...elements[def.manaType],
+              current: elements[def.manaType].current - drain,
+            };
           }
 
           newDisciplines[id] = { ...disc, xp: disc.xp + 1 };