#215 · zig-utils/zig-js

Parent: #134 Profile umbrella: #140 Home inventory: #163 Bun inventory: #164

Implement the pinned private-JSC Uint8Array constructor/identity boundary as real live objects rather than link-only shims:

Bun__createUint8ArrayForCopy
JSUint8Array__fromDefaultAllocator
JSBuffer__isBuffer

Acceptance criteria:

Return a live Uint8Array in the selected realm with the requested length.
Copy constructor copies non-null input and supports empty input.
Null copy input with non-zero length yields writable backing storage without reading the null pointer.
buffer=true records durable Bun Buffer identity and JSBuffer__isBuffer distinguishes it from ordinary Uint8Array values and non-cells.
Default-allocator constructor adopts non-empty bytes without copying and releases them exactly once with mi_free.
Standalone zig-js builds provide a weak libc-backed mi_free fallback; a consumer's strong mimalloc symbol wins when present.
Allocation/VM failures return the empty encoded value and publish the private pending exception.
Focused engine tests and the Home private consumer fixture cover copy isolation, null allocation, Buffer identity, zero length, pointer identity, and release-once behavior.
Home/Bun inventories, ABI docs, README scorecard, and parent trackers publish the new evidence and counts.

Completed evidence

Implemented in d50972ff and documented in 3b09f171. Focused tests passed 3/3 with zero leaks; the batched engine/consumer/audit gate passed 15/15; the Home consumer fixture passed 192/192. Home is 193/431 implemented (238 pending), Bun core is 187/421 (234 pending), and the public classifier reports 117 public, 19 extensions, and 197 private/support exports.