fix(audit-final): pre-merge hardening + expense receipt UI

Final audit pass on feat/berth-recommender (3 parallel Opus agents)
caught 5 critical and ~12 high-severity findings. All addressed in-branch;
medium/low items deferred to docs/audit-final-deferred.md.

Critical:
- Add filesystem-backend PUT handler at /api/storage/[token] so
  presigned uploads stop 405-ing in filesystem mode (every browser-driven
  berth-PDF + brochure upload was broken). Same token-verify + replay
  protection as GET, plus magic-byte gate when c=application/pdf.
- Forward req.signal into streamExpensePdf so an aborted 1000-receipt
  export no longer keeps grinding for minutes.
- Strengthen Content-Disposition filename sanitization: \s matches CR/LF
  which would let documentName forge headers; restrict to [\w. -]+ and
  add filename* RFC 5987 fallback.
- Lock public berths feed behind an explicit slug allowlist instead of
  ?portSlug= enumeration.
- Reject cross-port interest_berths upserts (defense-in-depth on top of
  the recommender SQL port filter).

High:
- Recommender: width-only feasibility now caps length via L/W ratio so a
  200ft berth doesn't surface for a 30ft beam request; total_interest_count
  filters out junction rows whose interest is in another port.
- Mooring normalization follow-up migration (0034) catches un-hyphenated
  padded forms (A01) the original 0024 WHERE missed.
- Send-out rate limit moved AFTER validation and scoped per-(port, user)
  so typos don't burn a slot and a multi-port rep can't be DoS'd by
  another tenant.
- Default-brochure path now blocks an archived row from sneaking through
  the partial unique index.
- NocoDB import --update-snapshot honoured under --dry-run so reps can
  refresh the seed JSON without committing DB writes.
- PDF export: orderBy desc(expenseDate); apply isNull(archivedAt) when
  expenseIds are passed (was bypassed); flag rate-unavailable rows with
  an amber footer instead of silently treating them as 1:1; skip the
  USD->EUR chain when source already matches target.
- expense-form-dialog: revokeObjectURL captures the URL in the closure
  instead of revoking the still-displayed one; reset upload state on
  close.
- scan/page: handleClearReceipt resets in-flight scan/upload mutations;
  Save disabled while upload pending.
- updateExpense re-asserts receipt-or-acknowledgement at the merged
  row so PATCH can't slip past the create-time refine.

Plus the in-progress receipt upload UI for the expense form dialog
(receipt picker + "I have no receipt" checkbox + warning banner) and
a noReceiptAcknowledged flag on ExpenseRow for edit-mode hydration.

Includes the canonical plan doc (referenced in CLAUDE.md), the handoff
prompt, and a deferred-findings index for follow-up issues.

1163/1163 vitest passing. Typecheck clean.

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

src/app/api/v1/expenses/export/pdf/route.ts

@@ -49,18 +49,25 @@ export const POST = withAuth(
             }
           : undefined,
         options: input.options,
+        // Forward the request abort signal so the streaming PDF builder
+        // stops fetching/resizing receipts the moment the client disconnects
+        // (otherwise an aborted 1000-receipt export keeps the worker busy
+        // for minutes after the user navigated away — see audit finding 2).
+        signal: req.signal,
       });
 
-      // NextResponse extends Response; passing a ReadableStream as the
-      // body keeps the streaming semantics. The wrapper's RouteHandler
-      // type expects NextResponse so we use it explicitly.
+      // Content-Disposition filename hardening: the validator caps length
+      // but `\s` matches CR/LF, which would let an attacker forge response
+      // headers. Strip everything that isn't word/space/dot/dash, AND set
+      // the RFC 5987 `filename*` so a UTF-8 body still survives.
+      const safeFilename = suggestedFilename.replace(/[^\w. \-]+/g, '_');
+      const disposition = `attachment; filename="${safeFilename}"; filename*=UTF-8''${encodeURIComponent(suggestedFilename)}`;
+
       return new NextResponse(stream, {
         status: 200,
         headers: {
           'Content-Type': 'application/pdf',
-          'Content-Disposition': `attachment; filename="${suggestedFilename}"`,
-          // The PDF is generated on the fly per-request and includes
-          // potentially-sensitive expense data; never cache.
+          'Content-Disposition': disposition,
           'Cache-Control': 'private, no-store, max-age=0',
           'X-Content-Type-Options': 'nosniff',
         },