Task 4.6: Add WASM Memory Overflow Detection

**Phase:** 4 - Risk Mitigation (High Priority)

**Tags:** feature, wasm

**Description:**
Implement overflow checks in `src/wasm/memoryManager.ts`.

**Acceptance Criteria:**
- [ ] Implement overflow checks in `src/wasm/memoryManager.ts`
- [ ] Add proper error handling
- [ ] Update tests