The two Gemini robustness nits raced the #774 merge: the patch landed on the
branch after GitHub had merged the pre-patch head, so main shipped the
architecture without the migration-input hardening. This re-lands ONLY the
robustness fixes — no identity-semantics change.
- chat/runtime.py: parse identity_scheme with try/except (TypeError, ValueError)
-> fallback to legacy scheme 1; revision str(... or '') so a null becomes ''
(unverifiable -> conservative DIVERGED), not the literal 'None'.
- workbench/readers.py: stored_revision=written_at_revision or '' so a None
revision is handled identically by the shared reconcile helper.
- tests: malformed identity_scheme does not crash the load guard (migrates);
reader falls back to legacy on malformed scheme; reader missing revision is a
conservative break.
Verified: 50 identity/migration/reader tests pass. No lane/serving path touched.
Removes code_revision from the engine-identity hash: engine_identity is now the
sha256 of the 5 ratified packs ONLY. The build revision is provenance (the
manifest's written_at_revision), not identity — so a behavior-neutral rebuild is
the SAME identity and the always-on daemon no longer flag-day strict-breaks on
every commit (the ADR-0220 defect).
Core:
- core/engine_identity.py: ratified_substrate/compute_engine_identity drop the
git_revision arg (packs-only); add compute_legacy_engine_identity (reproduces
the pre-split packs+rev hash, for migration verification), ENGINE_IDENTITY_SCHEME=2,
IdentityReconciliation enum, and reconcile_loaded_identity — the single source of
truth for the runtime guard AND the workbench reader.
- chat/runtime.py: the load guard reconciles via scheme. Current scheme -> direct
packs-only compare. Legacy (code_revision-folded) stamp -> a VERIFYING migration:
reconstruct the legacy hash from the persisted written_at_revision; a match proves
packs unchanged (warn + re-stamp, resume, no break) — a mismatch means the packs
genuinely changed (DIVERGED -> strict-refuse). Preserves 'distinct packs => refuse'.
- engine_state/save_manifest: stamp identity_scheme alongside engine_identity
(additive-optional; no schema_version bump).
- workbench/readers.py: continuity reader uses the same reconcile (no phantom break
on legacy checkpoints). cli.py break message reworded (packs, not 'build revision').
Callsite cleanup: drop the now-unused git_revision arg + imports across
always_on.py, evals/l10_always_on/runner.py, workbench/readers.py.
Tests:
- test_identity_provenance_split.py (new): 5 reconcile unit proofs + 3 runtime
integration proofs incl. the wrong=identity defense (legacy stamp of DIFFERENT
packs still strict-refuses) and the re-stamp migration.
- test_engine_identity.py: invert the code-revision test (rev no longer changes
identity); assert the substrate is packs-only.
- Restore 3 lineage tests silently red since ADR-0219 (flat-path _manifest helper
now resolves the gen-dir).
- Update remaining callsites/monkeypatches for the new signature.
Hygiene: .gitignore now covers the ADR-0219 gen-dir runtime files
(current, gen-*/, session_state.json, proposals.jsonl).
Verified: 59 identity/migration/lineage/workbench + 32 L10 + 76 invariants/cli +
34 smoke pass; serving lane SHAs unchanged (no derivation/reliability_gate touch).
