[§11.5 B7-SKILL] Skill memories first-class: parameters_schema at register, invocation_record, version surface

[alphaonedev]

Per FILE-ISSUE-B7 (epic doc §B7, tasks B7-SKILL-1/2). Current state (audited 2026-07-02 @ 6e756e7): version-chaining shipped at register (skill_register.rs supersedes prior row); parameters_schema accepted on the promote path only (skill_promote.rs, cli skill.rs) — NOT on skill_register; invocation_record/skill_invocations absent (PARAMETERS_SCHEMA const at field_names.rs:216 unused). Scope: accept+validate parameters_schema at register (fail closed at register, not activation — skill rows are admin-minted executable artefacts #949), invocation_record capture, version surfacing. Both backends (watch the #1552-class postgres-twin drift hazard). Effort M. Cross-link #1853.

[alphaonedev]

Closed by c0fbb4c on release/v0.9.0 (signed, Good).

STEP 0 schema determination: NO new schema needed — proceed (no vote required)

All three fields ride EXISTING structures, no migration on either backend:

• parameters_schema → stored in the existing skills.metadata JSON column (the same column L2-7's composes_with_reflections mirror already uses). The PARAMETERS_SCHEMA const at field_names.rs maps to that JSON key, not a new column.
• invocation_record → appends to the existing append-only signed_events table (a new event_types::SKILL_INVOKED = "skill.invoked" string is the only new vocabulary); NO skill_invocations table.
• version → pure read-side derivation over the EXISTING superseded_by version-chain (already written at register).
  CURRENT_SCHEMA_VERSION stays 78. No T1+T4 crossroads, no vote.

Deliverables

1. parameters_schema accepted + VALIDATED at REGISTER, fail-closed — memory_skill_register / ai-memory skill register --parameters-schema / POST /api/v1/skill/register. validate_parameters_schema runs BEFORE any DB write; a malformed schema is rejected at mint time (skills.rs: all 7 handlers lack header extraction — no caller gate on register/promote/export/get/list/resource/compose #949), never at activation. Same gate added to the promote path (previously a non-object schema was dropped silently).
2. invocation_record captured — memory_skill_get appends an unsigned skill.invoked signed_events row on each activation fetch and surfaces {event_id, recorded_at}.
3. version surfaced — on skill_register / skill_promote / skill_get responses.

Fail-closed validation test evidence

• handle_skill_register_rejects_malformed_parameters_schema — asserts the error contains "fail-closed" AND "must be a JSON object", AND SELECT COUNT(*) FROM skills == 0 (no row minted — rejection is BEFORE the write, not a rollback).
• skill_promote::rejects_malformed_parameters_schema_fail_closed — same, on the promote path.
• 8 validate_parameters_schema_* structural cases (non-object top-level/type/properties/property-entry, non-array required, required→unknown-property).

Both-backend parity

The skills/skill_resources tables have always been a sqlite-only substrate (no SAL trait / no postgres_schema.sql entry) — Agent Skills (v0.7.0 L1-5) is sqlite-native, so there is no postgres skill twin to drift (#1552 class avoided by construction). signed_events (which invocation_record rides) exists on BOTH backends with matching columns. Full cargo test --features sal-postgres suite: 0 failed (436 result summaries).

Full gate — all green

• fmt --check ✓ · clippy --all-targets --features sal-postgres -W pedantic -D warnings ✓
• check-hardcoded-literals ✓ · check-docs-vs-ssot ✓ (schema=78)
• build (default) ✓ · build --features sal-postgres ✓
• cargo test (default) 0 failed · cargo test --features sal-postgres 0 failed
• cargo llvm-cov --features sal,sal-postgres --lib --tests --workspace + check-thresholds: global 92.92% ≥ 90%, 179 modules pass / 0 fail. Touched modules: skill_register 97.72%, skill_get 99.27%, skill_promote 96.28%, cli/commands/skill 93.12%, signed_events 97.32% — all above the 90% floor.
• qual_10 module-size ceiling ✓

CI — all 8 workflows SUCCESS on c0fbb4c

tool-count-drift ✓ · c8-precheck ✓ · Mobile runtime ✓ · Bench ✓ · token-budget ✓ · Batman Mode acceptance gate ✓ · CI ✓ · Per-Module Coverage Thresholds ✓

Notes

• Snapshots re-blessed for the new memory_skill_register.parameters_schema property: tools_list_full.json via AI_MEMORY_BLESS_SNAPSHOTS=1; tool_definitions_pre_d1_6.json hand-patched (that specific test has no bless mechanism). No drift test weakened.
• validate_parameters_schema returns anyhow::Result per the QUAL-7 "new validation helpers should return Result<(), MemoryError> or anyhow" discipline (avoided a legacy-error-type ceiling bump rather than growing it).