perf(bookkeeping): fiscal-year pickers and cash accounts read the session cache (#1934)

First consumer migration onto lib/reference-data. FyPicker and
FiscalYearSelector (14 consumer surfaces, 47 fiscal-period fetch sites
before this series) now read useFiscalPeriods(); with the layout seed the
restore of the persisted scope runs in the first effect tick and onReady
fires on mount instead of after a round trip. Their restore rules are
extracted into a pure resolveInitialFiscalScope() (lib/reference-data/
fiscal-scope.ts) so the two pickers cannot drift apart again, and the
restore runs once per company load, not on every background revalidation.

- /reports: the static catalog renders immediately; only the "no fiscal
  year" empty state waits for the picker (previously six skeleton bars
  until /api/bookkeeping/fiscal-periods resolved).
- JournalEntryList (/bookkeeping): resolves its initial scope from the
  cached list instead of its own fetch; the saved-scope shortcut still
  unblocks the entries fetch first when nothing is cached, and resolution
  is guarded to once per company so a revalidation can never snap a
  deep-link "all years" visit back to the stored year.
- /transactions: the account chooser reads useCashAccounts({ enabledOnly })
  (seeded) instead of fetching /api/cash-accounts on every visit; the bank
  sync button invalidates that entry after a sync.
- STORAGE_KEY_PREFIX / ALL_YEARS_VALUE move to a dependency-free
  fiscal-year-storage.ts (re-exported from FiscalYearSelector) so lib/ code
  can import them without a React component.

raw-reference-fetch ratchet: 55 -> 51 files.

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

components/transactions/BankSyncNowButton.tsx

@@ -15,6 +15,7 @@ import {
 } from '@/components/ui/dropdown-menu'
 import { createClient } from '@/lib/supabase/client'
 import { notifyBankSyncUpdated } from '@/lib/transactions/bank-sync-signal'
+import { invalidateReferenceData } from '@/lib/reference-data/invalidate'
 import {
   claimConnectionsLoad,
   clearBusyConnection,
@@ -162,6 +163,9 @@ export function useBankSync() {
       // Tell the neighbouring status chip to refetch so it doesn't keep showing
       // the pre-sync "synced Nd ago" until a hard reload.
       notifyBankSyncUpdated()
+      // The account chooser reads cash accounts from the session cache
+      // (lib/reference-data); a sync can change balances, so refetch them.
+      void invalidateReferenceData('ref:cash-accounts')
       router.refresh()
     } catch (error) {
       toast({