audit: Tier 0 quick wins — EMAIL_REDIRECT_TO prod guard + storage routing + metadata masking

Tier 0.2: src/lib/env.ts now refuses boot when NODE_ENV=production AND
EMAIL_REDIRECT_TO is set. Sendmail logs the rewrite at warn (was debug)
so dev/staging windows where someone forgets to unset are immediately
visible.

Tier 0.6: backup_jobs.storage_path added to TABLES_WITH_STORAGE_KEYS in
src/lib/storage/migrate.ts. Flipping the storage backend used to
silently orphan every pg_dump artefact — last-resort recovery path is
now actually portable.

Tier 1.7: createAuditLog now runs metadata through maskSensitiveFields
(was only applied to old/new value diffs). Portal-auth, crm-invite,
hard-delete and email-accounts services were writing raw emails into
this column unbounded.

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

src/lib/email/index.ts

@@ -151,10 +151,21 @@ export async function sendEmail(
     ...(resolvedAttachments.length > 0 ? { attachments: resolvedAttachments } : {}),
   });
 
-  logger.debug(
-    { messageId: info.messageId, to: effectiveTo, originalTo: requestedTo, subject, portId },
-    env.EMAIL_REDIRECT_TO ? 'Email sent (redirected)' : 'Email sent',
-  );
+  // When EMAIL_REDIRECT_TO is set we elevate to `warn` so the dev-only
+  // safety net is visible in any logger config. Prod boot already refuses
+  // when both are set (see env.ts superRefine) — this catches the dev /
+  // staging window where someone left it in a .env by mistake.
+  if (env.EMAIL_REDIRECT_TO) {
+    logger.warn(
+      { messageId: info.messageId, to: effectiveTo, originalTo: requestedTo, subject, portId },
+      'Email sent (REDIRECTED via EMAIL_REDIRECT_TO — recipient overridden)',
+    );
+  } else {
+    logger.debug(
+      { messageId: info.messageId, to: effectiveTo, originalTo: requestedTo, subject, portId },
+      'Email sent',
+    );
+  }
 
   return info;
 }