feat: Sprint 1 core tracker + SuperOAuth PKCE E2E

Backend: cookie-parser, auth guard token introspection (SuperOAuth profile API),
fix réponse wrappée { success, data: { user, linkedProviders } }.
Frontend: page login 4 providers PKCE, callback SSR-safe (browser guard),
search améliorée (debounce, pagination, toast, feedback visuel ajout),
list complète (7 tabs, progression inline, score, vue grille/liste, cards goldées),
profil (XP bar, grades, 8 stats), user store partagé, toast system.

backend/package-lock.json

@@ -16,6 +16,7 @@
         "@nestjs/typeorm": "^11.0.0",
         "class-transformer": "^0.5.1",
         "class-validator": "^0.15.1",
+        "cookie-parser": "^1.4.7",
         "mysql2": "^3.20.0",
         "reflect-metadata": "^0.2.2",
         "rxjs": "^7.8.2",
@@ -24,6 +25,7 @@
       "devDependencies": {
         "@nestjs/cli": "^11.0.16",
         "@nestjs/schematics": "^11.0.9",
+        "@types/cookie-parser": "^1.4.10",
         "@types/express": "^5.0.6",
         "@types/node": "^25.5.0",
         "ts-node": "^10.9.2",
@@ -1176,6 +1178,16 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/cookie-parser": {
+      "version": "1.4.10",
+      "resolved": "https://registry.npmjs.org/@types/cookie-parser/-/cookie-parser-1.4.10.tgz",
+      "integrity": "sha512-B4xqkqfZ8Wek+rCOeRxsjMS9OgvzebEzzLYw7NHYuvzb7IdxOkI0ZHGgeEBX4PUM7QGVvNSK60T3OvWj3YfBRg==",
+      "dev": true,
+      "license": "MIT",
+      "peerDependencies": {
+        "@types/express": "*"
+      }
+    },
     "node_modules/@types/eslint": {
       "version": "9.6.1",
       "resolved": "https://registry.npmjs.org/@types/eslint/-/eslint-9.6.1.tgz",
@@ -2325,6 +2337,25 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/cookie-parser": {
+      "version": "1.4.7",
+      "resolved": "https://registry.npmjs.org/cookie-parser/-/cookie-parser-1.4.7.tgz",
+      "integrity": "sha512-nGUvgXnotP3BsjiLX2ypbQnWoGUPIIfHQNZkkC668ntrzGWEZVW70HDEB1qnNGMicPje6EttlIgzo51YSwNQGw==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "0.7.2",
+        "cookie-signature": "1.0.6"
+      },
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
+    "node_modules/cookie-parser/node_modules/cookie-signature": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
+      "integrity": "sha512-QADzlaHc8icV8I7vbaJXJwod9HWYp8uCqf1xa4OfNu1T7JVxQIrUgOWtHdNDtPiywmFbiS12VjotIXLrKM3orQ==",
+      "license": "MIT"
+    },
     "node_modules/cookie-signature": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.2.2.tgz",