feat(accounting): invoices force-enable the Accounting master

Invoice VAT config (codes + label) and the hourly rate now live under
Settings → Accounting, so an install with Invoices must have Accounting
available.

- applyDependencyRules (backend adminFeatureFlags.js + frontend
  FeatureFlagsContext.tsx): bills on → accounting on, before the
  accounting→children rule so the sub-features keep their own state.
- Migration 133 corrects existing installs: set the STORED accounting=true
  where bills is on. requireFeatureFlag('accounting') reads the raw row, so
  without this an upgraded install (invoices on, accounting off) would show
  the tab but 403 its endpoints. Idempotent; only flips on; no down.
- Features tab: the Accounting card shows locked-on (disabled + hint) while
  Invoices is enabled.

Also includes the i18n keys (en/de) for the VAT/financial settings move.

frontend/src/contexts/FeatureFlagsContext.tsx

@@ -91,6 +91,10 @@ function applyDependencyRules(flags: FeatureFlags): FeatureFlags {
   out.galleries = true;                            // foundation — always on
   if (out.quotes === false) out.bills = false;     // bills depend on quotes
   if (out.calendar === false) out.calendarBooking = false;  // booking depends on calendar
+  // Invoices (Bills) force-enable the Accounting master — invoice VAT config +
+  // hourly rate live under Settings → Accounting. Before the accounting→children
+  // rule so sub-features keep their own state.
+  if (out.bills === true) out.accounting = true;
   // Accounting sub-features require the Accounting master. Tax export is
   // independent of Bills now — it relocated permanently into Accounting.
   if (out.accounting === false) {

frontend/src/features/settings/tabs/FeaturesTab.tsx

@@ -324,6 +324,13 @@ export const FeaturesTab: React.FC = () => {
             sidebarLabel={t('settings.features.accounting.sidebar', 'Accounting')}
             enabled={staged.accounting}
             onToggle={(next) => setFlag('accounting', next)}
+            // Invoices force-enable Accounting (invoice VAT settings live here),
+            // so the master can't be turned off while Bills is on.
+            disabled={staged.bills}
+            lockedReason={staged.bills ? t(
+              'settings.features.accounting.requiredByBills',
+              'On automatically because Invoices is enabled — invoice VAT settings live in the Accounting section.',
+            ) : undefined}
           />
 
           <FeatureCard

frontend/src/i18n/locales/de.json

@@ -1646,7 +1646,8 @@
       "accounting": {
         "title": "Buchhaltung",
         "description": "Ein eigener Buchhaltungsbereich, getrennt vom CRM. Hier aktivieren und dann die Unterfunktionen unten einschalten (Steuerexport, Eingangsrechnungen). MwSt-/Steuerbehandlung dient nur als Orientierung — vor dem Verlassen darauf mit Ihrem Treuhänder prüfen.",
-        "sidebar": "Buchhaltung"
+        "sidebar": "Buchhaltung",
+        "requiredByBills": "Automatisch an, weil Rechnungen aktiviert ist — die MwSt-Einstellungen der Rechnungen liegen im Buchhaltungsbereich."
       },
       "incomingInvoices": {
         "title": "Eingangsrechnungen",
@@ -1731,7 +1732,16 @@
         "reclaimCountriesHint": "Üblicherweise Ihr Inland (CH / LI). Kosten aus anderen Ländern gelten als nicht abziehbare ausländische MwSt. Cmd/Ctrl-Klick für Mehrfachauswahl."
       },
       "disclaimer": "Sätze und MwSt-/Steuerbehandlung dienen nur als Orientierung — mit Ihrem Treuhänder prüfen.",
-      "savedToast": "Buchhaltungseinstellungen gespeichert."
+      "savedToast": "Buchhaltungseinstellungen gespeichert.",
+      "profileFields": {
+        "title": "MwSt-Bezeichnung & Stundensatz",
+        "vatLabel": "MwSt-Bezeichnung (z. B. MwSt., VAT)",
+        "vatLabelHint": "Wird als Bezeichnung der MwSt-Zeile auf Rechnungs-/Angebots-PDFs gedruckt. Leer lassen, um die Standardbezeichnung der Dokumentsprache zu verwenden.",
+        "hourlyRate": "Standard-Stundensatz",
+        "hourlyRatePlaceholder": "z. B. 120.00",
+        "hourlyRateHint": "Fallback, wenn ein Kunde keinen eigenen Satz hat. In {{currency}}, in Hauptwährungseinheiten. Leer lassen, um einen Satz pro Kunde oder pro Eintrag zu verlangen.",
+        "savedToast": "Gespeichert."
+      }
     }
   },
   "branding": {
@@ -3937,7 +3947,8 @@
     "vat": {
       "addTitle": "MWST-Code hinzufügen", "editTitle": "MWST-Code bearbeiten",
       "code": "Code", "name": "Name", "rate": "Satz %", "direction": "Richtung",
-      "account": "MWST-Konto", "noAccount": "— keines —", "confirmDelete": "Diesen MWST-Code löschen?"
+      "account": "MWST-Konto", "noAccount": "— keines —", "confirmDelete": "Diesen MWST-Code löschen?",
+      "legacyRate": "{{rate}}% (nicht konfiguriert)"
     },
     "export": {
       "title": "Treuhänder-Export",
@@ -4309,6 +4320,7 @@
   },
   "businessProfile": {
     "savedToast": "Geschäftsprofil gespeichert.",
+    "movedToAccounting": "MwSt-Satz, MwSt-Bezeichnung und Standard-Stundensatz befinden sich jetzt unter Einstellungen → Buchhaltung.",
     "title": "Geschäftsprofil",
     "subtitle": "Briefkopf, Kontaktdaten und Standardwerte für Angebote und Rechnungen.",
     "businessHours": {

frontend/src/i18n/locales/en.json

@@ -1204,7 +1204,8 @@
       "accounting": {
         "title": "Accounting",
         "description": "A dedicated Accounting area, separate from CRM. Turn this on, then enable the sub-features below (Tax export, Incoming invoices). VAT / tax treatment is guidance only — verify with your Treuhänder before relying on it.",
-        "sidebar": "Accounting"
+        "sidebar": "Accounting",
+        "requiredByBills": "On automatically because Invoices is enabled — invoice VAT settings live in the Accounting section."
       },
       "incomingInvoices": {
         "title": "Incoming invoices",
@@ -1289,7 +1290,16 @@
         "reclaimCountriesHint": "Typically your domestic country (CH / LI). Costs from other countries are treated as non-reclaimable foreign VAT. Cmd/Ctrl-click to multi-select."
       },
       "disclaimer": "Rates and VAT/tax treatment are guidance only — verify with your Treuhänder.",
-      "savedToast": "Accounting settings saved."
+      "savedToast": "Accounting settings saved.",
+      "profileFields": {
+        "title": "VAT label & hourly rate",
+        "vatLabel": "VAT label (e.g. MwSt., VAT)",
+        "vatLabelHint": "Printed as the VAT-line label on invoice / quote PDFs. Leave blank to use the document language default.",
+        "hourlyRate": "Default hourly rate",
+        "hourlyRatePlaceholder": "e.g. 120.00",
+        "hourlyRateHint": "Fallback used when a customer has no own rate. In {{currency}}, major units. Leave blank to require a per-customer or per-entry rate.",
+        "savedToast": "Saved."
+      }
     }
   },
   "analytics": {
@@ -3937,7 +3947,8 @@
     "vat": {
       "addTitle": "Add VAT code", "editTitle": "Edit VAT code",
       "code": "Code", "name": "Name", "rate": "Rate %", "direction": "Direction",
-      "account": "VAT account", "noAccount": "— none —", "confirmDelete": "Delete this VAT code?"
+      "account": "VAT account", "noAccount": "— none —", "confirmDelete": "Delete this VAT code?",
+      "legacyRate": "{{rate}}% (not configured)"
     },
     "export": {
       "title": "Treuhänder export",
@@ -4307,6 +4318,7 @@
   },
   "businessProfile": {
     "savedToast": "Business profile saved.",
+    "movedToAccounting": "The VAT rate, VAT label and default hourly rate now live under Settings → Accounting.",
     "title": "Business profile",
     "subtitle": "Issuer block shown on every quote and invoice PDF.",
     "businessHours": {