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/app/api/auth/resolve-identifier/route.ts

@@ -53,10 +53,7 @@ export async function POST(req: NextRequest) {
     const ip = clientIp(req);
     const rl = await checkRateLimit(ip, rateLimiters.auth);
     if (!rl.allowed) {
-      return NextResponse.json(
-        { email: '' },
-        { status: 429, headers: rateLimitHeaders(rl) },
-      );
+      return NextResponse.json({ email: '' }, { status: 429, headers: rateLimitHeaders(rl) });
     }
 
     const body = (await req.json().catch(() => ({}))) as { identifier?: string };