audit: 33-agent comprehensive audit + critical fixes

Full team audit run, all reports verbatim in docs/AUDIT-2026-05-12.md
(5900+ lines, 30+ critical findings). Already-fixed this commit:
- permission-overrides PUT: self-target block + RolePermissions allow-list + cross-tenant guard
- /api/auth/resolve-identifier: rate-limit + synthetic miss-email kill enumeration
- admin email-change: rotates account.accountId + revokes sessions
- middleware: token-gated email confirm/cancel routes whitelisted
- NAV_CATALOG: 10 dead-link sweeps to existing /admin/<x> targets

Feature work landing same commit: optional username sign-in
(migration 0054), per-user permission overrides (0055) with three-state
matrix tabbed inside UserForm, user disable button, role + outcome +
stage label normalisation across the platform, admin email-change
with auto-notification template.

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

src/lib/services/interests.service.ts

@@ -850,8 +850,7 @@ export async function changeInterestStage(
       ? (STAGE_LABELS[oldStage as PipelineStage] ?? oldStage.replace(/_/g, ' '))
       : 'unknown';
     const toLabel =
-      STAGE_LABELS[data.pipelineStage as PipelineStage] ??
-      data.pipelineStage.replace(/_/g, ' ');
+      STAGE_LABELS[data.pipelineStage as PipelineStage] ?? data.pipelineStage.replace(/_/g, ' ');
     await createNotification({
       portId,
       userId: meta.userId,