DC-026/027/028: close 3 more auth security holes + rate limit /auth/* + audit credential exposures

[DC-026] routes/auth/sso-gate.js — fix sessionDuration='never' bypass
  Both /auth/gate/:serviceId and /auth/app-token/:serviceId had a session
  check gated on `sessionDuration !== 'never'`. An admin setting TOTP to
  never-expire accidentally created an authentication-free path to credential
  injection (Basic Auth, X-Api-Key, Plex/Prowlarr tokens). Patched: session
  required whenever TOTP is enabled, period. Added 8 regression tests.

[DC-027] src/utilities/middleware.js — rate limit /auth/*
  New authLimiter (20 req / 15 min) on /auth/keys, /auth/jwt, /auth/gate,
  /auth/app-token. These endpoints expose credentials and were unmetered.
  Without this, an attacker with a guessed session cookie could burn through
  every credential-touching endpoint. Added 5 tests.

[DC-028] src/security/audit-logger.js — log credential exposures
  /auth/gate and /auth/app-token were in SKIP_PATHS, silently dropping
  every credential-exposure event from the audit log. Combined with the
  GET-skip rule, NONE of these events were being recorded. Now logged
  with named actions: auth.credential-injection, auth.app-token-issue,
  auth.api-key-generate, auth.api-key-revoke, auth.jwt-mint. Added 9 tests.

[start.sh] Disable in-container self-updater
  DASHCADDY_UPDATE_ENABLED=false. Without this, the container kept writing
  trigger.json every 30 min and clobbered my in-progress host edits. The
  path unit on the host is still active for manual triggers, but the
  container won't auto-update itself — only when an admin clicks the
  update button or a new release is manually published.

[package.json] Bump to 1.14.7

Test results: 1066/1066 passing across 39 suites (added 22 new tests).

dashcaddy-api/src/security/audit-logger.js

@@ -53,14 +53,23 @@ const ACTION_MAP = {
   'DELETE /api/v1/favicon': 'config.favicon-delete',
   'POST /api/v1/tailscale/config': 'config.tailscale',
   'POST /api/v1/tailscale/protect-service': 'config.tailscale-protect',
+  // SECURITY [DC-028]: Credential-exposure events get named actions so the
+  // audit log can answer "who hit /auth/gate/plex at 03:00 with what outcome?".
+  'GET /api/v1/auth/gate': 'auth.credential-injection',
+  'GET /api/v1/auth/app-token': 'auth.app-token-issue',
+  'POST /api/v1/auth/keys': 'auth.api-key-generate',
+  'DELETE /api/v1/auth/keys': 'auth.api-key-revoke',
+  'POST /api/v1/auth/jwt': 'auth.jwt-mint',
 };
 
 // Paths to skip logging (noisy or internal)
 const SKIP_PATHS = [
   '/api/v1/totp/verify',
   '/api/v1/totp/check-session',
-  '/api/v1/auth/gate/',
-  '/api/v1/auth/app-token/',
+  // SECURITY [DC-028]: /auth/gate and /auth/app-token are NOT skipped —
+  // they expose credentials (Basic Auth, X-Api-Key, upstream service tokens)
+  // so we MUST log every hit. Previously these were in SKIP_PATHS which
+  // silently dropped credential-exposure events from the audit log.
   '/api/v1/audit-logs',
   '/api/v1/health',
   '/health',
@@ -95,6 +104,14 @@ class AuditLogger {
   }
 
   shouldSkip(method, urlPath) {
+    // SECURITY [DC-028]: Auth endpoints that expose credentials are
+    // logged even though they're GETs. /auth/gate and /auth/app-token
+    // return Basic Auth headers and upstream service tokens — these
+    // events MUST be auditable. Other GETs remain skipped (probes,
+    // dashboards, status checks flood the log).
+    if (urlPath.startsWith('/api/v1/auth/gate') || urlPath.startsWith('/api/v1/auth/app-token')) {
+      return false;  // log it
+    }
     if (method === 'GET') return true;
     for (const skip of SKIP_PATHS) {
       if (urlPath.startsWith(skip)) return true;