fix(audit-wave-11): dossier sweep — error-ux + webhook + storage + search + maintainability

Final pass over the unaddressed AUDIT-2026-05-12 dossiers, taking the
tractable Critical/High items from each:

error-ux-auditor (5 items)
- C2: 17 toast.error(err.message) sites swept to toastError(err, …) so
  every user-visible failure carries a copy-paste Reference ID
- C3: apiFetch synthesizes a client-side correlation id when a 5xx
  comes back with a non-JSON body (reverse-proxy HTML pages); message
  becomes "The server is unreachable. Please try again." with code
  UPSTREAM_UNREACHABLE
- C4: checkRateLimit fails OPEN when Redis is unavailable so an outage
  no longer 500s login + portal sign-in; logged at warn so monitoring
  catches it
- H2: StorageTimeoutError (name='TimeoutError') replaces the plain
  Error throw in s3.ts withTimeout — error-classifier hints fire now
- H5: errorResponse() adopted across /api/storage/[token],
  /api/public/website-inquiries, and the Documenso webhook body (drops
  the "Invalid secret" reconnaissance string)

outbound-webhook-auditor (5 items)
- C1: signature is now HMAC(secret, `${ts}.${body}`) with the
  timestamp surfaced as X-Webhook-Timestamp so receivers can reject
  replays outside a freshness window
- C3: dead-letter with reason missing_signing_secret when secret is
  null (defence-in-depth against DB tampering / future migration
  mistakes)
- H2: webhooks queue bumped to maxAttempts=8 with 30 s base
  exponential backoff so a 30 s receiver blip during a deploy no
  longer dead-letters every in-flight event; per-queue
  backoffDelayMs added to QUEUE_CONFIGS
- M1: SSRF denylist gains Oracle Cloud metadata 192.0.0.192
- M2: dispatch-time https:// assertion before fetch, so a bad DB edit
  can't slip plaintext through

storage-pathing-auditor (2 items)
- H1: berth-PDF presigned-upload keys now `${portSlug}/berths/…/…`
  with portSlug threaded into backend.presignUpload — engages the
  filesystem-proxy port-binding `p` token verifier
- H2: presignDownloadUrl auto-derives portSlug from the key's first
  segment when callers don't pass it, so all 8 download sites engage
  the `p`-token guard without per-site plumbing

search-auditor (1 item)
- H3: removed dead void wantEmail; void wantPhone; pair plus the
  unused looksLikeEmail helper — the bucket-reorder it was scaffolded
  for was never wired

maintainability-auditor (1 item)
- M2: swept seven abandoned `void <symbol>` markers and their dead
  imports across clients/bulk, interests/bulk, admin/email-templates,
  admin/website-submissions, alert-rules, and notes.service

Deferred to future work (substantial refactors, schema migrations, or
multi-file UI work):
- error-ux M3-M8 (global-error.tsx, per-route loading.tsx coverage,
  ErrorBanner component, /api/ready route, worker DLQ admin surface)
- maintainability C1-C4 (documents/search/notes service splits,
  interest-tabs split — multi-hour refactors)
- currency C1-H5 (mixed-currency dashboard aggregation, FX history
  table, rounding policy) — wait for second non-USD port
- outbound-webhook C2 (deliveries reaper job), H1 (DNS-rebind TOCTOU
  with undici Agent), H3 (circuit-breaker), H5 (presigned-post-policy)
- storage-pathing C2 (orphan reaper), H3-H5 (streaming + content-type
  binding)

Tests: 1315/1315 vitest ✅ ; tsc clean.

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

src/app/api/storage/[token]/route.ts

@@ -21,7 +21,13 @@ import { Readable } from 'node:stream';
 import { NextRequest, NextResponse } from 'next/server';
 
 import { MAX_FILE_SIZE } from '@/lib/constants/file-validation';
-import { errorResponse } from '@/lib/errors';
+import {
+  AppError,
+  errorResponse,
+  ForbiddenError,
+  NotFoundError,
+  ValidationError,
+} from '@/lib/errors';
 import { logger } from '@/lib/logger';
 import { redis } from '@/lib/redis';
 import { FilesystemBackend, getStorageBackend } from '@/lib/storage';
@@ -47,16 +53,13 @@ export async function GET(
 
   const backend = await getStorageBackend();
   if (!(backend instanceof FilesystemBackend)) {
-    return NextResponse.json(
-      { error: 'Storage proxy is only available in filesystem mode' },
-      { status: 404 },
-    );
+    return errorResponse(new NotFoundError('storage proxy'));
   }
 
   const result = verifyProxyToken(token, backend.getHmacSecret(), 'get');
   if (!result.ok) {
     logger.warn({ reason: result.reason }, 'Storage proxy token rejected');
-    return NextResponse.json({ error: 'Invalid or expired token' }, { status: 403 });
+    return errorResponse(new ForbiddenError('Invalid or expired token'));
   }
   const { payload } = result;
 
@@ -72,7 +75,7 @@ export async function GET(
   const setOk = await redis.set(replayKey, '1', 'EX', remainingSeconds, 'NX');
   if (setOk !== 'OK') {
     logger.warn({ key: payload.k }, 'Storage proxy token replay rejected');
-    return NextResponse.json({ error: 'Token already used' }, { status: 403 });
+    return errorResponse(new ForbiddenError('Token already used'));
   }
 
   let absolutePath: string;
@@ -80,22 +83,22 @@ export async function GET(
     absolutePath = backend.resolveKeyForProxy(payload.k);
   } catch (err) {
     logger.warn({ err, key: payload.k }, 'Storage proxy key resolution failed');
-    return NextResponse.json({ error: 'Invalid key' }, { status: 400 });
+    return errorResponse(new ValidationError('Invalid key'));
   }
 
   let size: number;
   try {
     const stat = await fs.stat(absolutePath);
     if (!stat.isFile()) {
-      return NextResponse.json({ error: 'Not found' }, { status: 404 });
+      return errorResponse(new NotFoundError('file'));
     }
     size = stat.size;
   } catch (err) {
     const code = (err as NodeJS.ErrnoException).code;
     if (code === 'ENOENT') {
-      return NextResponse.json({ error: 'Not found' }, { status: 404 });
+      return errorResponse(new NotFoundError('file'));
     }
-    throw err;
+    return errorResponse(err);
   }
 
   // Convert the Node Readable into a Web ReadableStream for NextResponse.
@@ -140,16 +143,13 @@ export async function PUT(
 
   const backend = await getStorageBackend();
   if (!(backend instanceof FilesystemBackend)) {
-    return NextResponse.json(
-      { error: 'Storage proxy is only available in filesystem mode' },
-      { status: 404 },
-    );
+    return errorResponse(new NotFoundError('storage proxy'));
   }
 
   const result = verifyProxyToken(token, backend.getHmacSecret(), 'put');
   if (!result.ok) {
     logger.warn({ reason: result.reason }, 'Storage proxy upload token rejected');
-    return NextResponse.json({ error: 'Invalid or expired token' }, { status: 403 });
+    return errorResponse(new ForbiddenError('Invalid or expired token'));
   }
   const { payload } = result;
 
@@ -164,7 +164,7 @@ export async function PUT(
   const setOk = await redis.set(replayKey, '1', 'EX', remainingSeconds, 'NX');
   if (setOk !== 'OK') {
     logger.warn({ key: payload.k }, 'Storage proxy upload token replay rejected');
-    return NextResponse.json({ error: 'Token already used' }, { status: 403 });
+    return errorResponse(new ForbiddenError('Token already used'));
   }
 
   // Pre-flight size check via Content-Length so a malicious caller can't
@@ -172,14 +172,17 @@ export async function PUT(
   const contentLengthHeader = req.headers.get('content-length');
   const contentLength = contentLengthHeader ? Number(contentLengthHeader) : NaN;
   if (Number.isFinite(contentLength) && contentLength > MAX_FILE_SIZE) {
-    return NextResponse.json(
-      { error: `File exceeds ${MAX_FILE_SIZE} byte cap (Content-Length: ${contentLength})` },
-      { status: 413 },
+    return errorResponse(
+      new AppError(
+        413,
+        `File exceeds ${MAX_FILE_SIZE} byte cap (Content-Length: ${contentLength})`,
+        'PAYLOAD_TOO_LARGE',
+      ),
     );
   }
 
   if (!req.body) {
-    return NextResponse.json({ error: 'Empty body' }, { status: 400 });
+    return errorResponse(new ValidationError('Empty body'));
   }
 
   // Read the body into a buffer with a hard cap. Filesystem deployments are
@@ -200,9 +203,8 @@ export async function PUT(
         } catch {
           /* ignore */
         }
-        return NextResponse.json(
-          { error: `File exceeds ${MAX_FILE_SIZE} byte cap` },
-          { status: 413 },
+        return errorResponse(
+          new AppError(413, `File exceeds ${MAX_FILE_SIZE} byte cap`, 'PAYLOAD_TOO_LARGE'),
         );
       }
       chunks.push(Buffer.from(value));
@@ -210,7 +212,7 @@ export async function PUT(
     buffer = Buffer.concat(chunks);
   } catch (err) {
     logger.warn({ err, key: payload.k }, 'Storage proxy upload read failed');
-    return NextResponse.json({ error: 'Upload read failed' }, { status: 400 });
+    return errorResponse(new ValidationError('Upload read failed'));
   }
 
   // Magic-byte gate: when the token was minted with `c=application/pdf`
@@ -218,9 +220,8 @@ export async function PUT(
   // that isn't actually a PDF. Mirrors the post-upload check in
   // berth-pdf.service.ts so the two paths behave identically.
   if (payload.c === 'application/pdf' && !isPdfMagic(buffer)) {
-    return NextResponse.json(
-      { error: 'Uploaded file failed PDF magic-byte check (does not start with %PDF-).' },
-      { status: 400 },
+    return errorResponse(
+      new ValidationError('Uploaded file failed PDF magic-byte check (does not start with %PDF-).'),
     );
   }