fix: auth /social-providers endpoint ids (#115)

The `/social-providers` endpoint should return a list of the provider ids, not their names.
This was found when trying to use the microsoft endpoint and the endpoint was returning `"microsoft entraid"`, when the `AuthForm` expects it to just be `"microsoft"`.

.vscode/launch.json

@@ -6,7 +6,7 @@
       "type": "node-terminal",
       "request": "launch",
       "command": "pnpm dev",
-      "cwd": "${workspaceFolder}/apps/nextjs",
+      "cwd": "${workspaceFolder}/apps/web",
       "skipFiles": ["<node_internals>/**"],
       "sourceMaps": true,
       "sourceMapPathOverrides": {
@@ -14,4 +14,4 @@
       }
     }
   ]
-}
+}