fix: discipline reset on mana depletion and re-activation after stop

- #143: processTick now removes drained disciplines from activeIds and calls onStopPracticing so currentAction resets to 'meditate'
- #144: Removed paused guard from canProceedDiscipline so stopped disciplines can be re-activated
- Updated test to match new expected behavior for paused disciplines

src/lib/game/__tests__/discipline-math.test.ts

@@ -230,12 +230,12 @@ describe('canProceedDiscipline', () => {
     expect(result).toBe(true);
   });
 
-  it('should return false when discipline is paused', () => {
+  it('should return true when discipline is paused (paused state is handled by activate, not canProceedDiscipline)', () => {
     const state: DisciplineState = { id: 'raw-mastery', xp: 0, paused: true };
     const result = canProceedDiscipline(rawMastery, state, {
       rawMana: 1000,
     });
-    expect(result).toBe(false);
+    expect(result).toBe(true);
   });
 
   it('should return true when raw mana is sufficient', () => {