Adopt inference-only selected creates from mdbase-rs

[callumalpass]

Pins merged mdbase-rs fc1dc077 (callumalpass/mdbase-rs#78) and its reviewed spec dependency, including the direct Connect interop dependency and matching source in both lockfiles. No wire protocol, provider schema, release version, recovery policy or public artifact is changed by this PR.

The engine permits selected/contract-selected creates with empty explicit keys when final persisted membership matches. Configured explicit declarations retain authority. Auxiliary schemas, CEL failures, final serialization policy and lifecycle guards remain enforced.

Upstream: full Rust CI passed Linux/macOS/Windows, strict lint/features/docs, PostgreSQL17 and packaging; nine shared spec fixtures passed in Rust and TypeScript. App161 is merged/web-deployed/TestFlight1.0.3-build15. TS0.3.0-rc.6 is npm-published and archive integrity verified.

Integration correction: initial merge-group CI correctly rejected an incomplete lock update because I missed Connect’s direct interop manifest pin. Updated that pin; merged beta100 main; checked out the exact pinned Rust source locally. FULL cargo metadata --locked and cargo check --locked -p mdbase-connect-runtime now pass, as do formatting/release validators. No lock regeneration without review or test weakening. Requalifying exact merge-group CI before merge.

Release coordination: beta100 was prepared in #430, now merged. This PR retains its main-line changes and only updates the engine/spec dependency identities. Include it before freezing the release source. Existing signed-bundle/migration/acceptance/soak/production gates remain mandatory; this PR is not a backend deployment claim.

[callumalpass]

Exact corrected qualification run34908193460 remains RED; no merge/deployment. All compilation/runtime interop and the normal provider/system/rollback lanes passed, but two blockers remain:

1. retained_v2_inputs in test/upgrade/retained-v2.sh requires candidate deploy/docker/mdbase-rs-revision to be byte-identical to beta95 (76ceed). The requested engine update to fc1dc necessarily differs. This needs an explicit reviewed engine-change compatibility boundary and actual retained/read-write evidence—not deleting the guard or restoring the old engine just to turn CI green. Exact predecessor digest/tag, capability schemas, migration bytes and authority-inventory assertions must remain enforced.
2. Windows recursive_directory_changes_translate_once_and_only_current_paths_resolve observed one watcher event instead of two and timed out. No timeout enlargement or assumption that it is harmless.

The earlier missing direct Cargo manifest pin is corrected; full locked metadata and runtime compilation pass locally on the exact pinned sibling source. Detailed private evidence and release coordination are recorded in the canonical ops thread. The App web/TestFlight and TS npm publications are independent and succeeded; the new Connect backend is not deployed.

[callumalpass]

User explicitly requested removing the engine-revision equality gate. Commit1aae7a43 removes only that comparison; no revision allowlist or replacement approval mechanism. Exact predecessor identity, wire-schema equality, migration checks and the actual rollback/reupgrade authority-preservation assertions remain. Regression coverage confirms the distinction. Node24 focused tests16/16 and pnpm test:fast passed locally. The subsequent browser integration run exceeded the combined600-second command budget; not claimed passing. Fresh CI/actual retained-v2 qualification is required; the prior Windows watcher failure remains separate.