ABI: implement generic no-copy ArrayBuffer and TypedArray adoption

[chrisbbreuer]

Parent: #134
Profile umbrella: #140
Home inventory: #163
Bun inventory: #164
Builds on: #215, #216, and #217

Implement the pinned private-JSC no-copy exports:

• Bun__makeArrayBufferWithBytesNoCopy
• Bun__makeTypedArrayWithBytesNoCopy

Acceptance criteria:

• ArrayBuffer creation adopts the exact non-empty byte pointer and length without copying.
• TypedArray creation supports every pinned numeric TypedArrayType tag: Int8, Uint8, Uint8Clamped, Int16, Uint16, Int32, Uint32, Float16, Float32, Float64, BigInt64, and BigUint64.
• TypedArray length is floor(byte_length / element_size) while the adopted backing ArrayBuffer retains the full byte length, matching JSC for trailing bytes.
• TypeNone, DataView, unknown tags, and non-empty null pointers fail explicitly through the private pending exception boundary.
• Empty input returns live zero-length objects without dereferencing the pointer.
• The caller-supplied deallocator and context run exactly once at GC/realm teardown; null deallocators are supported without inventing ownership callbacks.
• Allocation or view-construction failures release transferred storage exactly once and never publish a partial object.
• Focused tests and the Home consumer fixture cover pointer identity, all tags, trailing bytes, empty input, invalid tags, callback context, exactly-once release, and public accessor compatibility.
• Inventories, ABI docs, README scorecard, and parent trackers publish the verified counts; benchmark scores remain unchanged unless a benchmark path is rerun.

Completed evidence

Implemented in d8396f26 and documented in c8ffaf00. Focused tests passed 3/3 with zero leaks; the batched engine/consumer/audit gate passed 15/15; the Home consumer fixture passed 198/198. Home is 199/431 implemented (232 pending), Bun core is 193/421 (228 pending), and the public classifier reports 117 public, 19 extensions, and 203 private/support exports.

[chrisbbreuer]

Completed on main in d8396f2 and c8ffaf0. Focused tests: 3/3, zero leaks. Batched verification: 15/15. Home fixture: 198/198. Home/Bun/public audits are current and green.