Memory-pressure regression misses remaining GC clock and timer traps

The GC failure reported in #56 still occurs when Go reads wall time or polls timers during `cabi_realloc`. Both can trap with `cannot leave component instance`.

The memory-pressure test added in #60 does not reliably trigger these paths. Strengthening it exposes both failures on Go 1.26.3 and 1.27.1 with the Wasmtime 48.0.2 adapter.

Regression test: #78. Adapter fix: https://github.com/bytecodealliance/wasmtime/pull/14319, extending the clock pause from https://github.com/bytecodealliance/wasmtime/pull/13563.