Unimem core implementation

Root accepted the existing narrow feature/core-import plan on 2026-10-16 under the owner's standing implementation request. The frozen PLAN's requirement for a different-vendor review was self-authored; no such verdict exists or is claimed. Independent Codex CODE review is the current review route under the owner's Node ban. The historical PLAN packet and parent evidence remain unchanged.

Source parent: Honeycrisp 9cbd48070a136e24711896c930670fcff8a147fc. Current native-test sibling: clean committed Strata 56aedb2d12b3126c601eb333419136d403614dbb. Historical tests used Strata 494df7a0973ae10a6cc1c2022e644d70449a29d6; their records retain that identity. New parent and candidate inputs are hashed before/after each command. The new parent repeats the frozen E0152 consumer, owning native tests and isolated native tests before production. The isolated consumer has no Strata dependency.

Implementation preserves default std queue behavior and adds an explicit no-default mode: queue alloc is always available, std forwards explicitly, runtime namespaces use core, and unit tests import their std prelude items. All three fixture bodies are unchanged from the frozen proposal. The durable compile-only gate adds a checked temporary-directory creation guard after root review; its original body and the narrow bridge are retained in the resume audit. Existing test bodies, native contracts, Cargo.lock and dependency versions remain unchanged. Rustfmt only reordered the new core import before the queue import in grid.rs before candidate capture.

Evidence: resume receipt. Owner branch: research/unimem-core; checkout: honeycrisp/.worktrees/unimem-core/honeycrisp. Agent: /root/foundation_resume_audit, Codex session 01a0d380-ada9-7ff0-8fcf-4057387fde96. Independent Codex source CODE review approved the delta; the separate gate supplement and actual gate results are retained in the resume audit. Owner tests, isolated tests, owner formatting and strict library Clippy pass. Broader inherited workspace gates remain red; the historical API/product gates remain unmet. Retain the checkout for root integration. No commit, push, merge, version, tag or publication is performed by this implementation agent. Physical-address, native Image ownership, completion and platform coverage remain separate requirements.