feat(frontend): Finalize auth refactor, routing, and resolve all code review findings

frontend/package-lock.json

@@ -18,6 +18,7 @@
         "react": "^19.2.0",
         "react-dom": "^19.2.0",
         "react-hook-form": "^7.71.1",
+        "react-router-dom": "^7.13.0",
         "tailwind-merge": "^3.4.0",
         "tailwindcss": "^4.1.18",
         "zod": "^4.3.6"
@@ -8711,6 +8712,57 @@
         }
       }
     },
+    "node_modules/react-router": {
+      "version": "7.13.0",
+      "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.13.0.tgz",
+      "integrity": "sha512-PZgus8ETambRT17BUm/LL8lX3Of+oiLaPuVTRH3l1eLvSPpKO3AvhAEb5N7ihAFZQrYDqkvvWfFh9p0z9VsjLw==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "^1.0.1",
+        "set-cookie-parser": "^2.6.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/react-router-dom": {
+      "version": "7.13.0",
+      "resolved": "https://registry.npmjs.org/react-router-dom/-/react-router-dom-7.13.0.tgz",
+      "integrity": "sha512-5CO/l5Yahi2SKC6rGZ+HDEjpjkGaG/ncEP7eWFTvFxbHP8yeeI0PxTDjimtpXYlR3b3i9/WIL4VJttPrESIf2g==",
+      "license": "MIT",
+      "dependencies": {
+        "react-router": "7.13.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      }
+    },
+    "node_modules/react-router/node_modules/cookie": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
+      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
     "node_modules/react-style-singleton": {
       "version": "2.2.3",
       "resolved": "https://registry.npmjs.org/react-style-singleton/-/react-style-singleton-2.2.3.tgz",
@@ -9008,6 +9060,12 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/set-cookie-parser": {
+      "version": "2.7.2",
+      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
+      "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
+      "license": "MIT"
+    },
     "node_modules/setprototypeof": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz",