chore: bump deps and modernize test loops

- release.yml: download-artifact v7 -> v8
- frontend: i18next 26.3.1 -> 26.3.2, qs 6.15.2 -> 6.15.3
- go.mod: consolidate indirect requires (go mod tidy)
- tests: adopt Go 1.22 range-over-int loops

frontend/package.json

@@ -30,10 +30,10 @@
     "axios": "^1.18.1",
     "codemirror": "^6.0.2",
     "dayjs": "^1.11.21",
-    "i18next": "^26.3.1",
+    "i18next": "^26.3.2",
     "otpauth": "^9.5.1",
     "persian-calendar-suite": "^1.5.5",
-    "qs": "^6.15.2",
+    "qs": "^6.15.3",
     "react": "^19.2.7",
     "react-dom": "^19.2.7",
     "react-i18next": "^17.0.8",