feat(database): add explicit atomic single-record mutations

[Upd4ting]

Contract

Adds a direct instance-scoped Table.atomicMutation primitive for revision-checked constant patch/delete and narrowly scoped scalar-equality deletion. Conditions belong inside the native target mutation; generic filtered writes do not satisfy this contract. MissingRevision is absent-field-only, never null or absent record. Unknown acknowledgements never become mismatch or trigger automatic retry.

Verification

• GitHub CI run34854533459 passes at head0d492469fd3bccb3ab712e62d0062452e3c2d4a4.
• pnpm test: 171 passing, including 10 new interface encoding/validation/outcome/type tests in the normal suite.
• Build, full formatting, lint, Knip, and git diff --check pass. Lint reports six existing warnings in files unchanged from origin/main.
• Local Oxc allocation failure was resolved by temporarily enabling memory overcommit only in the disposable orb, then restoring its original value; no repository rules or configuration were weakened.
• Native concurrency and acknowledgement-loss behavior is verified separately by MongoDB PR33, PostgreSQL PR4, and the RethinkDB adapter PR. No multi-record transaction guarantee is added.

Draft prerequisite

Keep draft until compatible adapters and the consumer graph are verified. Version remains 0.1.4 and is not published. PostgreSQL declared columns cannot distinguish absent revision from null; missing bootstrap requires supported overflow storage or explicit rejection. No merge, release, deployment, or shared-data migration is authorized by this PR.