Fix/chrome pdf preview csp (#572)

* feat: add option to exclude year-end closing entries in SIE export and related reports

* delete docs

* fix: allow Chrome's PDF viewer in verifikat document preview

The /api/documents/:id/inline route shipped with
`object-src 'none'` in its CSP, which blocked Chrome's built-in PDF
viewer (it renders inline PDFs via an internal <embed>). Users on
Chrome saw "Det här innehållet har blockerats" when expanding a PDF
attachment in the bookkeeping view; Firefox (PDF.js) and Edge (own
viewer) were unaffected, and JPGs worked because <img> isn't subject
to object-src.

Drops the CSP for this route to the minimum needed for embeddability:
`frame-ancestors 'self'`. X-Content-Type-Options: nosniff plus the
fixed Content-Type from the handler already block MIME confusion;
X-Frame-Options: SAMEORIGIN + frame-ancestors still block clickjacking.

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

* feat(auth): add webmail deep link to email confirmation screens

Mirrors Stripe's signup UX: after asking the user to verify their email,
detect their webmail provider from the domain and show a button that
opens the inbox in a new tab. Gmail gets a from:<sender> search
pre-populated; Outlook/Yahoo/iCloud/Proton open the inbox directly.
Unknown / custom domains fall back to the existing copy.

Sender address is configurable via NEXT_PUBLIC_BRANDING_AUTH_EMAIL_FROM
(default noreply@gnubok.se) so white-label installs can match their
Supabase Auth SMTP config.

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

* fix(auth): unblock first-time password set for BankID users with MFA

Supabase rejects updateUser({password}) and mfa.unenroll with "AAL2 session
is required" whenever a TOTP factor is enrolled. BankID magic-link logins
produce AAL1, and middleware skips MFA enforcement for bankid_linked users,
so they had no path to AAL2 — leaving them unable to set a backup password
or disable MFA without going through the email-recovery escape hatch.

- /api/account/password: branch on app_metadata.has_password. First-time set
  writes via service.auth.admin.updateUserById (no existing credential to
  protect, AAL2 guard does not apply). Change-password keeps the user-session
  updateUser so AAL2 still fires for credential rotation.
- /mfa/verify: accept a safeReturnTo query param and route there after
  successful verify, so step-up flows can land back where they came from.
- SecuritySettings: detect the AAL2 error from both change-password and
  mfa.unenroll and redirect through /mfa/verify?returnTo=/settings/account
  instead of toasting a dead-end error.

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

* Add tests and rounding utility for öre precision in bokslut calculations

- Implemented `roundOre` function for rounding SEK amounts to two decimal places, ensuring consistent monetary calculations.
- Introduced `ORE_TOLERANCE` constant for comparing rounded amounts, facilitating invariant checks in financial entries.
- Created comprehensive tests for `roundOre`, covering typical cases, edge cases, and idempotency.
- Added year-end invariants tests to verify database-level guarantees for closing entries, ensuring they balance to the öre and reject discrepancies.
- Developed end-to-end tests for the dispositions chain, validating the correctness of calculations across various scenarios.

* fix: update PDF rendering to remove Swish QR code generation and set default to disable Swish visibility

* fix: enhance security by rejecting data URIs in safeReturnTo function tests

* fix: improve rounding logic in roundOre function and add customer_type migration

* fix: add customer_type column to customers and enforce CHECK constraint

---------

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

lib/core/documents/document-service.ts

@@ -264,6 +264,85 @@ export async function linkToJournalEntry(
   return data as DocumentAttachment
 }
 
+export type DeleteDocumentResult =
+  | { ok: true; document: Pick<DocumentAttachment, 'id' | 'file_name'> }
+  | { ok: false; reason: 'not_found' | 'linked_to_entry'; status: number; message: string }
+
+/**
+ * Delete a document if and only if it is not yet linked to a journal entry.
+ *
+ * BFL 7 kap 2§: once a document is attached to a verifikation it becomes
+ * räkenskapsinformation and may not be deleted within the 7-year retention
+ * window. Linked docs must be superseded via createNewVersion() instead.
+ * The block_document_deletion() trigger is the DB-level backstop.
+ */
+export async function deleteDocument(
+  supabase: SupabaseClient,
+  companyId: string,
+  documentId: string
+): Promise<DeleteDocumentResult> {
+  const { data: doc, error: fetchError } = await supabase
+    .from('document_attachments')
+    .select('id, file_name, storage_path, journal_entry_id, user_id')
+    .eq('id', documentId)
+    .eq('company_id', companyId)
+    .maybeSingle()
+
+  if (fetchError || !doc) {
+    return {
+      ok: false,
+      reason: 'not_found',
+      status: 404,
+      message: 'Underlaget hittades inte.',
+    }
+  }
+
+  if (doc.journal_entry_id) {
+    return {
+      ok: false,
+      reason: 'linked_to_entry',
+      status: 409,
+      message:
+        'Underlaget är knutet till en verifikation och utgör räkenskapsinformation enligt Bokföringslagen 7 kap 2§. Räkenskapsinformation ska bevaras i minst 7 år och får inte raderas. Använd "Ersätt med ny version" om underlaget behöver korrigeras.',
+    }
+  }
+
+  const { error: deleteError } = await supabase
+    .from('document_attachments')
+    .delete()
+    .eq('id', documentId)
+    .eq('company_id', companyId)
+
+  if (deleteError) {
+    const msg = (deleteError as { message?: string }).message ?? ''
+    if (msg.includes('Bokföringslagen') || msg.includes('retention')) {
+      return {
+        ok: false,
+        reason: 'linked_to_entry',
+        status: 409,
+        message:
+          'Underlaget kan inte tas bort på grund av Bokföringslagens bevarandekrav (7 kap 2§).',
+      }
+    }
+    throw new Error(`Failed to delete document: ${msg}`)
+  }
+
+  if (doc.storage_path) {
+    await supabase.storage.from('documents').remove([doc.storage_path])
+  }
+
+  await eventBus.emit({
+    type: 'document.deleted',
+    payload: {
+      document: { id: doc.id, file_name: doc.file_name },
+      userId: doc.user_id,
+      companyId,
+    },
+  })
+
+  return { ok: true, document: { id: doc.id, file_name: doc.file_name } }
+}
+
 /**
  * Verify document integrity by re-hashing and comparing
  */