feat: add per-element mana regen disciplines for all 14 mana types

- Create data/disciplines/elemental-regen.ts (base + utility elements)
- Create data/disciplines/elemental-regen-advanced.ts (composite + exotic)
- Wire into ALL_DISCIPLINES via index.ts and discipline-slice.ts
- Add perElementRegenBonus to ComputedEffects type
- Merge regen_{element} discipline bonuses in computeAllEffects()
- Apply per-element regen to element mana each tick in gameStore
- Add 'Elemental Regen' and 'Advanced Regen' tabs to DisciplinesTab UI

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-05-25T09:51:14.159Z",
+    "generated": "2026-05-25T09:55:35.204Z",
     "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."
   },