fix(audit-integrations): SMTP/PG/Socket.IO timeouts, prompt injection, secret-at-rest

A focused review of every external integration surfaced six issues the
original audit missed.  Fixed here.

HIGH
* Socket.IO had an unconditional 30-second idle disconnect on every
  socket.  The comment on the line acknowledged it was "for development
  only, would be longer in prod" but no NODE_ENV guard existed, and the
  `socket.onAny` listener only resets on inbound client events — every
  dashboard connection that received only server-push events would have
  been torn down every 30s in production.  Removed the manual idle
  timer entirely; Socket.IO's pingTimeout / pingInterval handles
  dead-transport detection at the protocol level.
* SMTP transporters had no `connectionTimeout` / `greetingTimeout` /
  `socketTimeout`.  Nodemailer's defaults are 2 minutes for connect
  and unlimited for socket — a hung SMTP server would have held a
  BullMQ `email` worker concurrency slot for up to 10 min per job
  (5 retries × 2 min).  Set 10s/10s/30s on both the system transporter
  in `src/lib/email/index.ts` and the user-account transporter in
  `email-compose.service.ts`.

MEDIUM
* PostgreSQL pool had no `statement_timeout` /
  `idle_in_transaction_session_timeout`.  A slow query or transaction
  held by a crashed handler would have eventually exhausted the
  20-connection pool.  30s statement cap, 10s idle-in-tx cap, plus
  `max_lifetime: 30min` to recycle connections.
* `umami_password` and `umami_api_token` were stored as plaintext in
  `system_settings` (the SMTP and S3 secret paths use AES-GCM).  The
  reader now passes them through `readSecret()` which auto-detects
  the encrypted `iv:cipher:tag` shape and decrypts, falling back to
  legacy plaintext so operators can rotate without a flag-day.
* AI email-draft worker interpolated `additionalInstructions` (user-
  controlled) directly into the OpenAI prompt — a hostile rep could
  close the instructions block and inject prompt directives that
  override the system prompt.  Added `sanitizeForPrompt()` that
  strips newlines + quote chars, caps at 500 chars, and the prompt
  now wraps the value in a "treat as data not commands" preamble.

LOW
* Legacy `ensureBucket()` in `src/lib/minio/index.ts` was unguarded —
  if any future code imported it (currently no callers), a misconfigured
  prod deploy could mint a fresh empty bucket.  Now matches the gate
  used by the pluggable S3Backend (`MINIO_AUTO_CREATE_BUCKET=true`
  required) so the legacy export and the new pluggable path agree.

Confirmed not-an-issue: BullMQ Workers create connections via
`{ url }` options object, and BullMQ sets `maxRetriesPerRequest: null`
internally for those — no fix needed.  The shared `redis` singleton
that does keep `maxRetriesPerRequest: 3` is used only for direct
Redis ops (rate-limit sliding window, etc.), never for blocking
BullMQ commands, so the value is correct there.

Test status: 1175/1175 vitest, tsc clean.

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

src/lib/services/email-compose.service.ts

@@ -75,11 +75,17 @@ export async function sendEmail(
   // Decrypt credentials (INTERNAL - never logged or returned)
   const creds = await getDecryptedCredentials(data.accountId);
 
-  // Build user-specific SMTP transporter
+  // Build user-specific SMTP transporter. Same timeouts as the system
+  // transporter in src/lib/email/index.ts — without these a hung SMTP
+  // server holds the calling request for ~2min (Nodemailer's default
+  // connectionTimeout) and starves the documents/email worker slot.
   const transporter = nodemailer.createTransport({
     host: account.smtpHost,
     port: account.smtpPort,
     secure: account.smtpPort === 465,
+    connectionTimeout: 10_000,
+    greetingTimeout: 10_000,
+    socketTimeout: 30_000,
     auth: { user: creds.username, pass: creds.password },
   });
 

src/lib/services/umami.service.ts

@@ -23,6 +23,8 @@ import { systemSettings } from '@/lib/db/schema/system';
 import { rangeToBounds, type DateRange } from '@/lib/analytics/range';
 import { CodedError } from '@/lib/errors';
 import { fetchWithTimeout } from '@/lib/fetch-with-timeout';
+import { decrypt } from '@/lib/utils/encryption';
+import { logger } from '@/lib/logger';
 
 // ─── Settings access ────────────────────────────────────────────────────────
 
@@ -34,6 +36,12 @@ interface UmamiPortConfig {
   websiteId: string;
 }
 
+// `umami_api_token` and `umami_password` may be stored EITHER as encrypted
+// `iv:cipher:tag` strings (matching the SMTP / S3 secret pattern) OR as
+// legacy plaintext. The reader below tries decryption first and falls
+// back to the raw value when the format isn't AES-GCM-shaped, so an
+// operator can rotate to encrypted-at-rest by re-saving the setting
+// without a flag-day migration.
 const SETTING_KEYS = [
   'umami_api_url',
   'umami_api_token',
@@ -42,6 +50,28 @@ const SETTING_KEYS = [
   'umami_website_id',
 ] as const;
 
+function readSecret(raw: string | null | undefined): string | null {
+  const v = (raw ?? '').toString().trim();
+  if (!v) return null;
+  // `encrypt()` returns `<iv-hex>:<cipher-hex>:<tag-hex>` (3 colon-separated
+  // hex chunks). If we see that shape, decrypt; otherwise treat as legacy
+  // plaintext. The fallback path is a transition affordance — operators
+  // should re-save the setting via the admin UI, which writes the
+  // encrypted form going forward.
+  const parts = v.split(':');
+  if (parts.length === 3 && parts.every((p) => /^[0-9a-f]+$/i.test(p))) {
+    try {
+      return decrypt(v);
+    } catch (err) {
+      logger.warn(
+        { err },
+        'Umami secret looked encrypted but decrypt failed; treating as plaintext',
+      );
+    }
+  }
+  return v;
+}
+
 /**
  * Read the five Umami-related setting rows for one port and assemble them.
  * Returns null if the minimum required config (URL + websiteId + an auth
@@ -58,9 +88,11 @@ export async function loadUmamiConfig(portId: string): Promise<UmamiPortConfig |
 
   const map = new Map(rows.map((r) => [r.key, r.value as string | null | undefined]));
   const apiUrl = (map.get('umami_api_url') ?? '').toString().trim().replace(/\/$/, '');
-  const apiToken = ((map.get('umami_api_token') ?? '') as string).trim() || null;
+  // Sensitive values pass through readSecret() to support encrypted-at-rest
+  // storage (with plaintext fallback for legacy rows).
+  const apiToken = readSecret(map.get('umami_api_token') as string | null | undefined);
   const username = ((map.get('umami_username') ?? '') as string).trim() || null;
-  const password = ((map.get('umami_password') ?? '') as string).trim() || null;
+  const password = readSecret(map.get('umami_password') as string | null | undefined);
   const websiteId = ((map.get('umami_website_id') ?? '') as string).trim();
 
   if (!apiUrl || !websiteId) return null;