fix(reconciliation): secondary-account scoping, dialog clipping, and N:1 matching (#624)

* fix(reconciliation): secondary-account scoping, dialog clipping, and N:1 matching

Three follow-ups to per-account bank reconciliation (PR #623):

- Secondary same-currency accounts (e.g. a 1931 savings account) double-counted
  the company's unassigned (NULL cash_account_id) transactions, inflating their
  bank total and showing a large bogus difference while 1930 still reconciled.
  Only the primary cash account now claims NULL rows; every other account scopes
  strictly to its own id. `includeUnassigned` is threaded through all
  status/run/list call sites from cash_accounts.is_primary.

- The "Matcha mot befintlig verifikation" picker's dropdown was absolutely
  positioned inside the dialog's overflow-y-auto container and got clipped. Add
  an `inline` mode that renders the candidate list in normal flow; the dialog
  uses it, the reconciliation view keeps the compact overlay.

- N:1 matching: several bank transactions can now settle one verifikat (a salary
  run paid in multiple transfers, an invoice paid in instalments). New
  get_account_gl_lines_for_matching RPC surfaces already-matched vouchers with a
  linked_transaction_count behind a "Visa även matchade verifikationer" toggle;
  manualLink's 1:1 guard is relaxed (the aggregate difference still catches
  mis-links).

Tests: extended bank-reconciliation unit tests (strict scope + N:1), rewrote the
cash_account_id isolation pg test to prove NULL rows land on the primary account
only, and added a pg test for the new RPC.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(reconciliation): address PR review — accurate "att matcha mot" count

- BankReconciliationView: the "N verifikationer att matcha mot" hint counted
  glLines (which includes already-matched vouchers when "Visa matchade" is on),
  overcounting the vouchers that still need a transaction. Use unmatchedGlLines
  so the label is correct regardless of the toggle (matches the table below).
- MatchVerifikationPicker: document that `open` is overlay-only; the setOpen()
  writes are intentional no-ops in inline mode.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/api/transactions/route.ts

@@ -41,15 +41,20 @@ export async function GET(request: Request) {
 
   let derivedCurrency = currency
   let cashAccountId: string | undefined
+  // Only the primary account claims unassigned (NULL cash_account_id) rows, so
+  // a secondary same-currency account's lists match its status card instead of
+  // pooling the primary's unassigned rows. See scopeTransactionsToAccount.
+  let includeUnassigned = true
   if (accountNumberParam) {
     const { data: cashAccount } = await supabase
       .from('cash_accounts')
-      .select('id, currency')
+      .select('id, currency, is_primary')
       .eq('company_id', companyId)
       .eq('ledger_account', accountNumberParam)
       .maybeSingle()
     if (cashAccount) {
       cashAccountId = cashAccount.id as string
+      includeUnassigned = Boolean(cashAccount.is_primary)
       if (!derivedCurrency && cashAccount.currency) derivedCurrency = cashAccount.currency as string
     }
   }
@@ -79,7 +84,7 @@ export async function GET(request: Request) {
   // Shares one implementation with the reconciliation lib so the filter shape
   // can't drift between the status card and these lists.
   if (cashAccountId || derivedCurrency) {
-    query = scopeTransactionsToAccount(query, cashAccountId, derivedCurrency ?? 'SEK')
+    query = scopeTransactionsToAccount(query, cashAccountId, derivedCurrency ?? 'SEK', includeUnassigned)
   }
   if (dateFrom) query = query.gte('date', dateFrom)
   if (dateTo) query = query.lte('date', dateTo)