0.18.0

Changed

• Rebuilding an instance from its events (rehydrate) now holds every event to what the kernel would have written for it, in execute's own order. Per event: an operation event's changed must be exactly what the emitting operation's set: writes from the arguments that event records (one operation has to accept the arguments under its argument schema and preconditions and produce the fields, because one execute call did); a creation event's changed must equal its recorded fields; then the folded fields are validated against the schema and the invariants evaluated, after each event rather than once at the end. A legacy history that folded before is refused if any event's changed was hand-written or was produced by a definition whose set: has since changed, or if a step falls short of the schema or an invariant; the refusal names the event index, its type, the operation tried and the fields in dispute. An event whose type no operation emits on its transition, and a creation event whose type is not the one create.emit names, are refused outright: an event nothing emits describes no decision. A revision is folded as one decision: its events must agree on transition, arguments and fields, must be exactly the operation's emits in order, and each payload must be what its template resolves to — so an operation with two emits now folds (its second event was refused as a revision gap before) and a forged payload is refused. Fold your histories before upgrading, and keep an emitter declared for every event type your histories still carry.
• entity create --store and entity execute --store now run through the shared stored runtime that the generated CLI and the MCP tools already use. execute --store takes an optional --expected-revision N (default: the revision the store holds when the command runs). Repeating an accepted --record-id with the same operation, arguments, provenance and expected revision returns the original record even after the subject has advanced; the same id with different intent is refused as record_conflict; a stale --expected-revision is refused as revision_conflict before the kernel runs. Store refusals now carry a kind field in their JSON, the same vocabulary MCP reports, and execute --store on an id the store does not hold is a store refusal (exit 1, kind: not_found) rather than an invalid invocation (exit 2). --instance and --store now conflict instead of --instance being silently ignored.
• A before/after operand that is a literal must now be an instant the kernel reads (YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS[.fff][Z]). A definition carrying an unreadable literal — an impossible date, an offset-bearing timestamp, a number, null, a list — used to register and then refuse every evaluation as unobservable while naming nothing to observe; it is now refused at registration as an invalid rule naming the operand and the forms that are read.
• entity-sqlite builds on rusqlite 0.40.2 (libsqlite3-sys 0.38.2, still bundled), up from 0.32.1: the SQLite this provider compiles in moves with it. No API or schema change.
• Move the scheduled comparison with current AEP lifecycle documents to Atlas; deterministic fixture and pin checks remain in the local gate. Refresh the fixture from current AEP source and cover the executable-system-specification lifecycle and its conformance evidence requirement.

Fixed

• entity generate rust-cli no longer fails with cannot open built binary …/release/<name> when Cargo's output location is overridden. The build directory is made absolute before use, so a relative --build-dir — including the default build/entity-runtime/<name> — is no longer resolved a second time against itself; --target-dir <build-dir>/target keeps CARGO_TARGET_DIR or a build.target-dir in a parent .cargo/config.toml from moving the build; and the generator installs the executable Cargo reports having built rather than guessing its path, so a CARGO_BUILD_TARGET or build.target that inserts a target-triple component is followed.
• The hybrid store's divergence detail for a replica-accepted, authority-refused write no longer carries a run of spaces before the error text.

Documentation

• Added a subsystem and derivation map distinguishing the runtime from ESS and generated domain surfaces. Updated adoption examples to 0.17.7, completed the generated CLI workflow, and clarified exact retries, event/history coverage, optional queries, and trusted-host responsibilities.