feat(financial-reports): add charts, trends and forecasts overview tab

Adds a new "نمای کلی و نمودارها" tab to the financial reports page with
KPI cards, daily/weekly income-trend and monthly breakdown charts, a
payment-status doughnut, a due-date cash-flow forecast chart, and full
per-class income and upcoming-payments tables — backed by chart.js /
vue-chartjs and the new /financial-reports/admin/analytics endpoint.

package.json

@@ -13,6 +13,7 @@
     "@fontsource/vazirmatn": "^5.3.0",
     "@primevue/themes": "4.0.7",
     "axios": "^1.19.0",
+    "chart.js": "^4.5.1",
     "filepond": "^4.32.12",
     "filepond-plugin-file-validate-type": "^1.2.9",
     "filepond-plugin-image-preview": "^4.6.12",
@@ -26,6 +27,7 @@
     "sass": "^1.102.0",
     "vee-validate": "^4.15.1",
     "vue": "^3.5.40",
+    "vue-chartjs": "^5.3.4",
     "vue-filepond": "^8.0.0",
     "vue-i18n": "^11.4.8",
     "vue-router": "^5.2.0",