fix(security): tier-0 audit blockers (next CVE, role gate, perm traps, key validation, rate limits)

Closes the five highest-risk findings from
docs/audit-comprehensive-2026-05-05.md so the platform is not exposed
while the rest of the audit backlog (1 CRIT + 18 HIGH + 32 MED + 23 LOW)
is worked through:

* CVE-2025-29927 — bump next 15.1.0 → 15.2.9; nginx strips
  X-Middleware-Subrequest at the edge as defense-in-depth.
* Cross-tenant role escalation — POST/PATCH/DELETE on /admin/roles now
  require super-admin (was: any holder of admin.manage_users).  Adds
  shared `requireSuperAdmin(ctx)` helper.
* Silent-403 traps — `documents.edit` and `files.edit` keys added to
  RolePermissions; seeded role values updated; migration 0041 backfills
  the new keys on every existing roles+port_role_overrides JSONB.  File
  routes remap the dead `create` action to `upload` / `manage_folders`.
* Berth-PDF / brochure register endpoints — reject body.storageKey
  unless it matches the namespace the matching presign endpoint issued
  (prevents repointing a tenant's PDF at foreign-port bytes).
* Portal auth rate limits — sign-in 5/15min/(ip,email),
  forgot-password 3/hr/IP, activate/reset/set-password 10/hr/IP.  Adds
  `enforcePublicRateLimit()` for non-`withAuth` routes.

Test status unchanged: 1168/1168 vitest, tsc clean.

Refs: docs/audit-comprehensive-2026-05-05.md (CRITICAL, HIGH §§1–4)

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

tests/helpers/factories.ts

@@ -316,6 +316,7 @@ export function makeFullPermissions(): RolePermissions {
     documents: {
       view: true,
       create: true,
+      edit: true,
       send_for_signing: true,
       upload_signed: true,
       delete: true,
@@ -337,7 +338,7 @@ export function makeFullPermissions(): RolePermissions {
       record_payment: true,
       export: true,
     },
-    files: { view: true, upload: true, delete: true, manage_folders: true },
+    files: { view: true, upload: true, edit: true, delete: true, manage_folders: true },
     email: { view: true, send: true, configure_account: true },
     reminders: {
       view_own: true,
@@ -393,6 +394,7 @@ export function makeViewerPermissions(): RolePermissions {
     documents: {
       view: true,
       create: false,
+      edit: false,
       send_for_signing: false,
       upload_signed: false,
       delete: false,
@@ -414,7 +416,7 @@ export function makeViewerPermissions(): RolePermissions {
       record_payment: false,
       export: false,
     },
-    files: { view: true, upload: false, delete: false, manage_folders: false },
+    files: { view: true, upload: false, edit: false, delete: false, manage_folders: false },
     email: { view: true, send: false, configure_account: false },
     reminders: {
       view_own: true,
@@ -470,6 +472,7 @@ export function makeSalesAgentPermissions(): RolePermissions {
     documents: {
       view: true,
       create: true,
+      edit: true,
       send_for_signing: true,
       upload_signed: true,
       delete: false,
@@ -491,7 +494,7 @@ export function makeSalesAgentPermissions(): RolePermissions {
       record_payment: false,
       export: false,
     },
-    files: { view: true, upload: true, delete: false, manage_folders: false },
+    files: { view: true, upload: true, edit: false, delete: false, manage_folders: false },
     email: { view: true, send: true, configure_account: false },
     reminders: {
       view_own: true,
@@ -547,6 +550,7 @@ export function makeSalesManagerPermissions(): RolePermissions {
     documents: {
       view: true,
       create: true,
+      edit: true,
       send_for_signing: true,
       upload_signed: true,
       delete: true,
@@ -568,7 +572,7 @@ export function makeSalesManagerPermissions(): RolePermissions {
       record_payment: true,
       export: true,
     },
-    files: { view: true, upload: true, delete: true, manage_folders: true },
+    files: { view: true, upload: true, edit: true, delete: true, manage_folders: true },
     email: { view: true, send: true, configure_account: false },
     reminders: {
       view_own: true,