db: agent enrollment schema (M4-4a, migration 0021) (#1482)

packages/db/src/schema.ts

@@ -302,6 +302,11 @@ export const agents = pgTable(
     skills: jsonb('skills').$type<string[]>(),
     isSystem: boolean('is_system').notNull().default(false),
     config: jsonb('config'),
+    // Enrollment (M4-4, docs/plans/2026-08-29-agent-enrollment-command-design.md §4).
+    // NULL on both marks a legacy (non-enrolled) row; no backfill — enrollment
+    // is a fact the rank-4 command creates, not one to invent for existing rows.
+    harness: text('harness'),
+    enrolledAt: timestamp('enrolled_at', { withTimezone: true }),
     createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
     updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
   },
@@ -1279,3 +1284,109 @@ export const hierarchyOutbox = pgTable(
     index('hierarchy_outbox_status_created_idx').on(t.status, t.createdAt),
   ],
 );
+
+// ---------------------------------------------------------------------------
+// Agent enrollment (M4-4) — rank-4 command family audit/outbox/fence stores.
+// Design: docs/plans/2026-08-29-agent-enrollment-command-design.md §4.
+// Pattern reuse from the hierarchy audit/outbox pair, separate store. Audit
+// rows reference the agent by snapshot id, deliberately with NO FK, so audit
+// history survives agent deletion through the legacy CRUD DELETE path.
+// Idempotency for this family lives in agent_idempotency_fence (contract 3
+// §4.3 envelope, ratified into contract 5 §4 via contract 3 §7 item 4) — the
+// audit and outbox tables carry no idempotency key of their own.
+
+export const AGENT_AUDIT_EVENT_TYPES = [
+  // Semantic mutation event of agent.enroll.
+  'agent.enrolled',
+  // Non-mutation access class: a passing idempotent replay appends this and
+  // nothing else (accessing principal, current correlation id, fence-row
+  // reference in the payload).
+  'agent.enrollment.replayed',
+] as const;
+
+export const agentAuditEvents = pgTable(
+  'agent_audit_events',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    // Global append order; per-agent ordering is a filter on agent_id ordered
+    // by seq.
+    seq: bigint('seq', { mode: 'number' }).notNull().generatedAlwaysAsIdentity(),
+    eventType: text('event_type').notNull(),
+    // No FK: audit events outlive every principal and every target.
+    actorId: text('actor_id').notNull(),
+    agentId: uuid('agent_id').notNull(),
+    correlationId: text('correlation_id').notNull(),
+    causationId: uuid('causation_id').references((): AnyPgColumn => agentAuditEvents.id, {
+      onDelete: 'restrict',
+    }),
+    // Immutable snapshot at event time; never carries credential material
+    // (§3.1 rule 1: actor, agent id, harness, provider, name, credentialMode).
+    payload: jsonb('payload').notNull(),
+    createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+  },
+  (t) => [
+    uniqueIndex('agent_audit_events_seq_idx').on(t.seq),
+    index('agent_audit_events_agent_seq_idx').on(t.agentId, t.seq),
+    index('agent_audit_events_correlation_idx').on(t.correlationId),
+    check(
+      'agent_audit_events_type_check',
+      sql`event_type IN ('agent.enrolled', 'agent.enrollment.replayed')`,
+    ),
+  ],
+);
+
+export const agentOutboxStatusEnum = pgEnum('agent_outbox_status', [
+  'pending',
+  'processing',
+  'delivered',
+]);
+
+export const agentOutbox = pgTable(
+  'agent_outbox',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    // FK into the append-only events table: never dangles, RESTRICT is safe.
+    eventId: uuid('event_id')
+      .notNull()
+      .references(() => agentAuditEvents.id, { onDelete: 'restrict' }),
+    correlationId: text('correlation_id').notNull(),
+    status: agentOutboxStatusEnum('status').notNull().default('pending'),
+    createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+    updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+    deliveredAt: timestamp('delivered_at', { withTimezone: true }),
+  },
+  (t) => [
+    uniqueIndex('agent_outbox_event_idx').on(t.eventId),
+    index('agent_outbox_status_created_idx').on(t.status, t.createdAt),
+  ],
+);
+
+// Contract 3 §4.3 fence shape. Uniqueness is (operation, key); the recorded
+// replay mode is always 'actor-bound' for this family (`shared` is seed-only
+// and refused at validation — design §3.1), but the column keeps the ratified
+// envelope shape and serves the mode-mismatch collision check. The payload
+// digest input EXCLUDES the credential value (design §3.1 rule 5).
+export const agentIdempotencyFence = pgTable(
+  'agent_idempotency_fence',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    operation: text('operation').notNull(),
+    idempotencyKey: text('idempotency_key').notNull(),
+    // No FK: fence rows outlive principals, mirroring the audit tables.
+    actorId: text('actor_id').notNull(),
+    authorizationScope: text('authorization_scope').notNull(),
+    payloadDigest: text('payload_digest').notNull(),
+    replayMode: text('replay_mode').notNull().default('actor-bound'),
+    // Committed-outcome reference (the enrolled agent's id). Snapshot value,
+    // no FK: the fence must keep answering replays after a legacy DELETE.
+    outcomeAgentId: uuid('outcome_agent_id').notNull(),
+    createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+  },
+  (t) => [
+    uniqueIndex('agent_idempotency_fence_operation_key_idx').on(t.operation, t.idempotencyKey),
+    check(
+      'agent_idempotency_fence_replay_mode_check',
+      sql`replay_mode IN ('actor-bound', 'shared')`,
+    ),
+  ],
+);