feat: discipline UI improvements - stat labels, prerequisites, mana type tab

- Add player-friendly label field to statBonus in DisciplineDefinition
- Show prerequisite requirements on locked discipline cards
- Disable activate button for locked disciplines
- Restructure elemental attunement into dedicated 'Mana Types' tab
- Add checkDisciplinePrerequisites utility function
- Update store to enforce prerequisite checking on activation
- Split discipline-prerequisites tests into separate file

docs/circular-deps.txt

@@ -1,5 +1,5 @@
 # Circular Dependencies
-Generated: 2026-05-25T10:43:13.495Z
+Generated: 2026-05-25T10:50:06.358Z
 Found: 6 circular chain(s) — these MUST be fixed before modifying involved files.
 
 1. Processed 134 files (1.4s) (2 warnings)

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-05-25T10:43:11.889Z",
+    "generated": "2026-05-25T10:50:04.757Z",
     "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."
   },

docs/project-structure.txt

@@ -200,6 +200,7 @@ Mana-Loop/
 │       │   │   ├── crafting-utils-recipe.test.ts
 │       │   │   ├── crafting-utils-time.test.ts
 │       │   │   ├── discipline-math.test.ts
+│       │   │   ├── discipline-prerequisites.test.ts
 │       │   │   ├── enemy-generator.test.ts
 │       │   │   ├── enemy-utils.test.ts
 │       │   │   ├── floor-utils.test.ts
@@ -248,6 +249,7 @@ Mana-Loop/
 │       │   │   │   ├── base.ts
 │       │   │   │   ├── elemental-regen-advanced.ts
 │       │   │   │   ├── elemental-regen.ts
+│       │   │   │   ├── elemental.ts
 │       │   │   │   ├── enchanter-special.ts
 │       │   │   │   ├── enchanter-spells.ts
 │       │   │   │   ├── enchanter-utility.ts