Add professor share & financial reports UI, expense management page

Adds payout configuration fields (percentage/hourly + per-session
expense allowance) with a live payout preview to the class form,
a new Financial Reports page (per-class and date-range/monthly tabs,
per-session drill-down dialog) with reusable stat cards, and an
Institutional Expenses management page. Registers routes, sidebar
navigation, and permission constants for the new financial_reports
and expenses permissions.

src/views/classes/ClassDetailView.vue

@@ -2,6 +2,15 @@
 <template>
   <div class="class-detail-view" v-if="classData">
     <PageHeader :title="classData.name" :subtitle="`دوره: ${classData.course?.title || '-'}`">
+      <PermissionGate permission="financial_reports:read">
+        <Button
+          label="گزارش مالی کلاس"
+          icon="pi pi-chart-line"
+          text
+          severity="info"
+          @click="$router.push(`/financial-reports?classId=${classId}`)"
+        />
+      </PermissionGate>
       <Button label="ویرایش" icon="pi pi-pencil" class="ml-2" @click="$router.push(`/classes/edit/${classId}`)" />
       <Button label="بازگشت" icon="pi pi-arrow-left" text severity="secondary" @click="$router.push('/classes')" />
     </PageHeader>