feat: add GitHub OAuth2 login and protect product mutations with JWT

- add /auth/login and /auth/callback (rewritten to pages/api/auth/*) for the
  GitHub Authorization Code flow, with a state cookie against login CSRF
- issue a 1h JWT after the code exchange and verify it (HS256) in the Apollo
  context; createProduct, updateProduct and deleteProduct require it
- set products.created_by from the logged-in GitHub user (upsert into users)
- preset the Authorization header in the embedded Sandbox
- add jsonwebtoken, drop unused cors, rename package to week-7

package-lock.json

@@ -1,19 +1,19 @@
 {
-  "name": "week-4",
+  "name": "week-7",
   "version": "1.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "week-4",
+      "name": "week-7",
       "version": "1.0.0",
       "license": "ISC",
       "dependencies": {
         "@apollo/server": "^5.5.1",
         "@as-integrations/next": "^4.1.0",
-        "cors": "^2.8.6",
         "dotenv": "^17.4.2",
         "graphql": "^16.14.2",
+        "jsonwebtoken": "^9.0.3",
         "next": "^16.3.4",
         "pg": "^8.23.0",
         "react": "^19.2.8",
@@ -1198,6 +1198,12 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/buffer-equal-constant-time": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/buffer-equal-constant-time/-/buffer-equal-constant-time-1.0.1.tgz",
+      "integrity": "sha512-zRpUiDwd/xk6ADqPMATG8vc9VPrkck7T07OIx0gnjmJAnHnTVXNQG3vfvWNuiZIkwu9KrKdA1iJKfsfTVxE6NA==",
+      "license": "BSD-3-Clause"
+    },
     "node_modules/bytes": {
       "version": "3.1.2",
       "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.1.2.tgz",
@@ -1397,6 +1403,15 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/ecdsa-sig-formatter": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/ecdsa-sig-formatter/-/ecdsa-sig-formatter-1.0.11.tgz",
+      "integrity": "sha512-nagl3RYrbNv6kQkeJIpt6NJZy8twLB/2vtz6yN9Z4vRKHN4/QZJIEbqohALSgwKdnksuY3k5Addp5lg8sVoVcQ==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "safe-buffer": "^5.0.1"
+      }
+    },
     "node_modules/ee-first": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
@@ -1677,6 +1692,91 @@
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       "license": "MIT"
     },
+    "node_modules/jsonwebtoken": {
+      "version": "9.0.3",
+      "resolved": "https://registry.npmjs.org/jsonwebtoken/-/jsonwebtoken-9.0.3.tgz",
+      "integrity": "sha512-MT/xP0CrubFRNLNKvxJ2BYfy53Zkm++5bX9dtuPbqAeQpTVe0MQTFhao8+Cp//EmJp244xt6Drw/GVEGCUj40g==",
+      "license": "MIT",
+      "dependencies": {
+        "jws": "^4.0.1",
+        "lodash.includes": "^4.3.0",
+        "lodash.isboolean": "^3.0.3",
+        "lodash.isinteger": "^4.0.4",
+        "lodash.isnumber": "^3.0.3",
+        "lodash.isplainobject": "^4.0.6",
+        "lodash.isstring": "^4.0.1",
+        "lodash.once": "^4.0.0",
+        "ms": "^2.1.1",
+        "semver": "^7.5.4"
+      },
+      "engines": {
+        "node": ">=12",
+        "npm": ">=6"
+      }
+    },
+    "node_modules/jwa": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/jwa/-/jwa-2.0.1.tgz",
+      "integrity": "sha512-hRF04fqJIP8Abbkq5NKGN0Bbr3JxlQ+qhZufXVr0DvujKy93ZCbXZMHDL4EOtodSbCWxOqR8MS1tXA5hwqCXDg==",
+      "license": "MIT",
+      "dependencies": {
+        "buffer-equal-constant-time": "^1.0.1",
+        "ecdsa-sig-formatter": "1.0.11",
+        "safe-buffer": "^5.0.1"
+      }
+    },
+    "node_modules/jws": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/jws/-/jws-4.0.1.tgz",
+      "integrity": "sha512-EKI/M/yqPncGUUh44xz0PxSidXFr/+r0pA70+gIYhjv+et7yxM+s29Y+VGDkovRofQem0fs7Uvf4+YmAdyRduA==",
+      "license": "MIT",
+      "dependencies": {
+        "jwa": "^2.0.1",
+        "safe-buffer": "^5.0.1"
+      }
+    },
+    "node_modules/lodash.includes": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/lodash.includes/-/lodash.includes-4.3.0.tgz",
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+      "license": "MIT"
+    },
+    "node_modules/lodash.isboolean": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isboolean/-/lodash.isboolean-3.0.3.tgz",
+      "integrity": "sha512-Bz5mupy2SVbPHURB98VAcw+aHh4vRV5IPNhILUCsOzRmsTmSQ17jIuqopAentWoehktxGd9e/hbIXq980/1QJg==",
+      "license": "MIT"
+    },
+    "node_modules/lodash.isinteger": {
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/lodash.isinteger/-/lodash.isinteger-4.0.4.tgz",
+      "integrity": "sha512-DBwtEWN2caHQ9/imiNeEA5ys1JoRtRfY3d7V9wkqtbycnAmTvRRmbHKDV4a0EYc678/dia0jrte4tjYwVBaZUA==",
+      "license": "MIT"
+    },
+    "node_modules/lodash.isnumber": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isnumber/-/lodash.isnumber-3.0.3.tgz",
+      "integrity": "sha512-QYqzpfwO3/CWf3XP+Z+tkQsfaLL/EnUlXWVkIk5FUPc4sBdTehEqZONuyRt2P67PXAk+NXmTBcc97zw9t1FQrw==",
+      "license": "MIT"
+    },
+    "node_modules/lodash.isplainobject": {
+      "version": "4.0.6",
+      "resolved": "https://registry.npmjs.org/lodash.isplainobject/-/lodash.isplainobject-4.0.6.tgz",
+      "integrity": "sha512-oSXzaWypCMHkPC3NvBEaPHf0KsA5mvPrOPgQWDsbg8n7orZ290M0BmC/jgRZ4vcJ6DTAhjrsSYgdsW/F+MFOBA==",
+      "license": "MIT"
+    },
+    "node_modules/lodash.isstring": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/lodash.isstring/-/lodash.isstring-4.0.1.tgz",
+      "integrity": "sha512-0wJxfxH1wgO3GrbuP+dTTk7op+6L41QCXbGINEmD+ny/G/eCqGzxyCsh7159S+mgDDcoarnBw6PC1PS5+wUGgw==",
+      "license": "MIT"
+    },
+    "node_modules/lodash.once": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/lodash.once/-/lodash.once-4.1.1.tgz",
+      "integrity": "sha512-Sb487aTOCr9drQVL8pIxOzVhafOjZN9UU54hiN8PU3uAiSV7lx1yYNpbNmex2PK6dSJoNTSJUUswT651yww3Mg==",
+      "license": "MIT"
+    },
     "node_modules/lodash.sortby": {
       "version": "4.7.0",
       "resolved": "https://registry.npmjs.org/lodash.sortby/-/lodash.sortby-4.7.0.tgz",
@@ -2175,7 +2275,6 @@
       "resolved": "https://registry.npmjs.org/semver/-/semver-7.8.5.tgz",
       "integrity": "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA==",
       "license": "ISC",
-      "optional": true,
       "bin": {
         "semver": "bin/semver.js"
       },