feat: real audit_log with redaction + pending_changes; replace stub

lib/db/migrations/006_audit.sql

@@ -0,0 +1,30 @@
+CREATE TABLE audit_log (
+  id          bigserial PRIMARY KEY,
+  actor_kind  text NOT NULL CHECK (actor_kind IN ('user','agent','cron','worker','system')),
+  actor_id    uuid,
+  entity_type text NOT NULL,
+  entity_id   uuid,
+  action      text NOT NULL CHECK (action IN ('create','update','delete','suggest','approve','reject')),
+  diff        jsonb,
+  occurred_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE TABLE pending_changes (
+  id          uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  agent_id    uuid NOT NULL REFERENCES agents(id) ON DELETE CASCADE,
+  entity_type text NOT NULL,
+  entity_id   uuid,
+  action      text NOT NULL CHECK (action IN ('create','update','delete')),
+  payload     jsonb NOT NULL,
+  reason      text,
+  status      text NOT NULL DEFAULT 'pending'
+              CHECK (status IN ('pending','approved','rejected')),
+  resolved_at timestamptz,
+  resolved_by text,
+  created_at  timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX idx_audit_entity ON audit_log(entity_type, entity_id, occurred_at);
+CREATE INDEX idx_audit_actor ON audit_log(actor_kind, actor_id, occurred_at);
+CREATE INDEX idx_pending_status ON pending_changes(status, created_at)
+  WHERE status='pending';

lib/db/repos/audit.js

@@ -0,0 +1,72 @@
+import { pool } from '../pool.js';
+
+const REDACT_KEYS = new Set([
+  'token','token_hash','password','api_key','secret','authorization'
+]);
+
+function isSensitiveKey(k) {
+  return REDACT_KEYS.has(String(k).toLowerCase());
+}
+
+function redactValueForKey(k, v) {
+  if (isSensitiveKey(k)) return '[REDACTED]';
+  return redact(v);
+}
+
+function redact(obj) {
+  if (!obj || typeof obj !== 'object') return obj;
+  if (Array.isArray(obj)) return obj.map(redact);
+  const out = {};
+  for (const [k, v] of Object.entries(obj)) {
+    out[k] = redactValueForKey(k, v);
+  }
+  return out;
+}
+
+function diff(before, after) {
+  if (before === null && after === null) return null;
+  if (before === null || before === undefined) return { kind: 'create', after: redact(after) };
+  if (after === null || after === undefined) return { kind: 'delete', before: redact(before) };
+  const changed = {};
+  for (const k of new Set([...Object.keys(before), ...Object.keys(after)])) {
+    if (JSON.stringify(before[k]) !== JSON.stringify(after[k])) {
+      changed[k] = {
+        before: redactValueForKey(k, before[k]),
+        after: redactValueForKey(k, after[k])
+      };
+    }
+  }
+  return Object.keys(changed).length ? { kind: 'update', changes: changed } : null;
+}
+
+export async function recordAudit(actor, action, entity_type, entity_id, before, after) {
+  const d = diff(before, after);
+  await pool.query(
+    `INSERT INTO audit_log(actor_kind, actor_id, entity_type, entity_id, action, diff)
+     VALUES($1,$2,$3,$4,$5,$6)`,
+    [actor?.kind || 'system', actor?.id || null, entity_type, entity_id, action, d]
+  );
+}
+
+export async function listForEntity(entity_type, entity_id, { limit = 100 } = {}) {
+  const { rows } = await pool.query(
+    `SELECT * FROM audit_log WHERE entity_type=$1 AND entity_id=$2
+     ORDER BY occurred_at DESC LIMIT $3`,
+    [entity_type, entity_id, limit]
+  );
+  return rows;
+}
+
+export async function listByActor({ actor_kind, actor_id, limit = 100 } = {}) {
+  const where = [], vals = [];
+  let i = 1;
+  if (actor_kind) { where.push(`actor_kind=$${i++}`); vals.push(actor_kind); }
+  if (actor_id) { where.push(`actor_id=$${i++}`); vals.push(actor_id); }
+  vals.push(limit);
+  const w = where.length ? `WHERE ${where.join(' AND ')}` : '';
+  const { rows } = await pool.query(
+    `SELECT * FROM audit_log ${w} ORDER BY occurred_at DESC LIMIT $${i}`,
+    vals
+  );
+  return rows;
+}

lib/db/repos/audit_stub.js

@@ -1,2 +1 @@
-// Replaced in Task 16 with real audit_log writes.
-export async function recordAudit() { /* noop until 006 migration lands */ }
+export { recordAudit } from './audit.js';

lib/db/repos/pending_changes.js

@@ -0,0 +1,32 @@
+import { pool } from '../pool.js';
+
+export async function create({ agent_id, entity_type, entity_id, action, payload, reason }) {
+  const { rows: [r] } = await pool.query(
+    `INSERT INTO pending_changes(agent_id, entity_type, entity_id, action, payload, reason)
+     VALUES($1,$2,$3,$4,$5,$6) RETURNING *`,
+    [agent_id, entity_type, entity_id || null, action, payload, reason || null]
+  );
+  return r;
+}
+
+export async function listPending({ limit = 100 } = {}) {
+  const { rows } = await pool.query(
+    `SELECT * FROM pending_changes WHERE status='pending' ORDER BY created_at LIMIT $1`,
+    [limit]
+  );
+  return rows;
+}
+
+export async function getById(id) {
+  const { rows: [r] } = await pool.query(`SELECT * FROM pending_changes WHERE id=$1`, [id]);
+  return r;
+}
+
+export async function resolve(id, status, resolved_by) {
+  const { rows: [r] } = await pool.query(
+    `UPDATE pending_changes SET status=$1, resolved_at=now(), resolved_by=$2
+     WHERE id=$3 AND status='pending' RETURNING *`,
+    [status, resolved_by || null, id]
+  );
+  return r;
+}