Motivation

Memory management bugs in JavaScript interop often only surface under extreme allocation pressure (see PR#393 which required 10-30 million allocations to reproduce). Current tests only validate normal usage patterns and don't catch memory leaks or reference counting issues that appear at system boundaries.

Summary

Adds comprehensive stress tests that push memory allocation to limits and test system behavior under extreme pressure to catch real memory management bugs.

Test Coverage

• Memory exhaustion: Allocates 25k+ objects until limits are reached
• Heap fragmentation: Tests recovery from fragmented allocation patterns
• Boundary conditions: Mixed allocation with exponentially increasing pressure
• Non-FinalizationRegistry scenarios: Focuses on manual memory management paths

Implementation

Tests use aggressive garbage collection and expect/handle memory exhaustion failures to validate reference counting mechanisms under stress.