feat(audit): comprehensive logging — auth events, severity, source, IP

Audit log was previously silent on authentication and on background
work. This wires:

- Login (success + failed) and logout via a wrapper around better-auth's
  [...all] handler. Failed logins are severity 'warning' and carry the
  attempted email so brute-force attempts surface in the inspector.
- New severity (info|warning|error|critical) and source (user|auth|
  system|webhook|cron|job) columns on audit_logs. permission_denied
  defaults to 'warning', hard_delete to 'critical'.
- Webhook delivery success/failure/DLQ/retry now write audit rows
  alongside the webhook_deliveries detail table.
- IP address is now visible as a column in the inspector (was already
  captured at the helper level).
- Audit UI: severity badges per row, severity + source dropdowns, IP
  column, expanded action filter covering hard-delete, webhook events,
  job/cron events.

Migration 0044 adds the two columns + their port-scoped indexes.
1175/1175 vitest passing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/api/auth/[...all]/route.ts

@@ -1,4 +1,146 @@
-import { auth } from '@/lib/auth';
+import type { NextRequest } from 'next/server';
 import { toNextJsHandler } from 'better-auth/next-js';
 
-export const { GET, POST } = toNextJsHandler(auth);
+import { auth } from '@/lib/auth';
+import { createAuditLog } from '@/lib/audit';
+import { logger } from '@/lib/logger';
+
+const upstream = toNextJsHandler(auth);
+
+/**
+ * Wrap better-auth's `[...all]` handler so we can stamp the audit log on
+ * authentication events. Better-auth itself doesn't fire any callback we
+ * can hook on sign-in / sign-out / failed-login — we inspect the route
+ * + response status after the upstream handler finishes.
+ *
+ *   Successful sign-in   → action 'login'  (severity info)
+ *   Failed sign-in       → action 'login'  (severity warning, ok=false)
+ *   Sign-out             → action 'logout' (userId resolved before cookie
+ *                                            is cleared)
+ *
+ * Audit writes are fire-and-forget (createAuditLog never throws).
+ */
+
+interface AuthBody {
+  user?: { id?: string; email?: string };
+  id?: string;
+  email?: string;
+}
+
+function clientMeta(req: NextRequest): { ipAddress: string; userAgent: string } {
+  const ip =
+    req.headers.get('x-forwarded-for')?.split(',')[0]?.trim() ?? req.headers.get('x-real-ip') ?? '';
+  return { ipAddress: ip, userAgent: req.headers.get('user-agent') ?? '' };
+}
+
+function logSignIn(args: {
+  req: NextRequest;
+  responseBody: string;
+  status: number;
+  attemptedEmail: string | null;
+}) {
+  const meta = clientMeta(args.req);
+  let parsed: AuthBody | null = null;
+  try {
+    parsed = JSON.parse(args.responseBody) as AuthBody;
+  } catch {
+    /* upstream returned non-JSON */
+  }
+  const userId = parsed?.user?.id ?? parsed?.id ?? null;
+  const email = parsed?.user?.email ?? parsed?.email ?? args.attemptedEmail ?? null;
+  const ok = args.status >= 200 && args.status < 300;
+
+  void createAuditLog({
+    userId,
+    portId: null,
+    action: 'login',
+    entityType: 'session',
+    entityId: userId ?? args.attemptedEmail ?? 'unknown',
+    metadata: {
+      ok,
+      status: args.status,
+      attemptedEmail: args.attemptedEmail ?? email ?? null,
+    },
+    ipAddress: meta.ipAddress,
+    userAgent: meta.userAgent,
+    severity: ok ? 'info' : 'warning',
+    source: 'auth',
+  });
+}
+
+async function logSignOut(req: NextRequest) {
+  const meta = clientMeta(req);
+  let userId: string | null = null;
+  try {
+    const session = await auth.api.getSession({ headers: req.headers });
+    userId = session?.user?.id ?? null;
+  } catch {
+    /* unauthenticated or expired */
+  }
+
+  void createAuditLog({
+    userId,
+    portId: null,
+    action: 'logout',
+    entityType: 'session',
+    entityId: userId ?? 'unknown',
+    metadata: {},
+    ipAddress: meta.ipAddress,
+    userAgent: meta.userAgent,
+    severity: 'info',
+    source: 'auth',
+  });
+}
+
+async function withAuthAudit(req: NextRequest): Promise<Response> {
+  const url = new URL(req.url);
+  const path = url.pathname;
+  const isSignIn = path.endsWith('/sign-in/email') || path.endsWith('/sign-in');
+  const isSignOut = path.endsWith('/sign-out');
+
+  // Read the request body BEFORE forwarding so we can extract the
+  // attempted email even when the credentials are wrong (the upstream
+  // handler will consume the body stream and we can't read it twice).
+  let attemptedEmail: string | null = null;
+  let forwardReq: NextRequest = req;
+  if (isSignIn && req.method === 'POST') {
+    try {
+      const raw = await req.text();
+      try {
+        attemptedEmail = (JSON.parse(raw) as { email?: string }).email ?? null;
+      } catch {
+        /* form-encoded or non-JSON */
+      }
+      // Reconstruct a fresh Request so the upstream handler can read it.
+      forwardReq = new Request(req.url, {
+        method: req.method,
+        headers: req.headers,
+        body: raw,
+      }) as unknown as NextRequest;
+    } catch (err) {
+      logger.warn({ err }, 'Failed to read sign-in body for audit');
+    }
+  }
+
+  // Capture sign-out userId BEFORE the upstream handler clears the cookie.
+  const signOutPromise = isSignOut ? logSignOut(req) : null;
+
+  const res = await upstream.POST(forwardReq);
+
+  if (isSignIn) {
+    try {
+      const body = await res.clone().text();
+      logSignIn({ req, responseBody: body, status: res.status, attemptedEmail });
+    } catch (err) {
+      logger.warn({ err }, 'Failed to capture sign-in response for audit');
+    }
+  }
+  if (signOutPromise) void signOutPromise;
+
+  return res;
+}
+
+export const GET = upstream.GET;
+export async function POST(req: NextRequest): Promise<Response> {
+  return withAuthAudit(req);
+}

src/app/api/v1/admin/audit/route.ts

@@ -15,6 +15,8 @@ const auditQuerySchema = z.object({
   action: z.string().optional(),
   userId: z.string().optional(),
   entityId: z.string().optional(),
+  severity: z.enum(['info', 'warning', 'error', 'critical']).optional(),
+  source: z.enum(['user', 'system', 'auth', 'webhook', 'cron', 'job']).optional(),
   dateFrom: z.string().optional(),
   dateTo: z.string().optional(),
   /** Free-text query against the tsvector `search_text` column. */
@@ -39,6 +41,8 @@ export const GET = withAuth(
         action: query.action,
         entityType: query.entityType,
         entityId: query.entityId,
+        severity: query.severity,
+        source: query.source,
         from: query.dateFrom ? new Date(query.dateFrom) : undefined,
         to: query.dateTo ? new Date(query.dateTo) : undefined,
         cursor,