feat(auth): add authentication endpoints (#6265)

**What**
- Add authentication endpoints: 
  - `/auth/[scope]/[provider]` 
  - `/auth/[scope]/[provider]/callback`
- update authenticate-middleware handler
- Add scope field to user
- Add unique constraint on scope and entity_id

note: there's still some remaining work related to jwt auth to be handled, this is mainly focussed on session auth with endpoints



Co-authored-by: Sebastian Rindom <7554214+srindom@users.noreply.github.com>

packages/auth/src/models/auth-provider.ts

@@ -20,8 +20,8 @@ export default class AuthProvider {
   @Property({ columnType: "text" })
   name: string
 
-  @Enum({ items: () => ProviderDomain, default: ProviderDomain.ALL })
-  domain: ProviderDomain = ProviderDomain.ALL
+  @Property({ columnType: "text", nullable: true })
+  scope: string
 
   @Property({ columnType: "jsonb", nullable: true })
   config: Record<string, unknown> | null = null

packages/auth/src/models/auth-user.ts

@@ -17,7 +17,10 @@ import { generateEntityId } from "@medusajs/utils"
 type OptionalFields = "provider_metadata" | "app_metadata" | "user_metadata"
 
 @Entity()
-@Unique({ properties: ["provider","entity_id" ], name: "IDX_auth_user_provider_entity_id" })
+@Unique({
+  properties: ["provider", "scope", "entity_id"],
+  name: "IDX_auth_user_provider_scope_entity_id",
+})
 export default class AuthUser {
   [OptionalProps]: OptionalFields
 
@@ -34,14 +37,17 @@ export default class AuthUser {
   })
   provider: AuthProvider
 
+  @Property({ columnType: "text" })
+  scope: string
+
   @Property({ columnType: "jsonb", nullable: true })
   user_metadata: Record<string, unknown> | null
 
-  @Property({ columnType: "jsonb", nullable: true })
-  app_metadata: Record<string, unknown> | null
+  @Property({ columnType: "jsonb" })
+  app_metadata: Record<string, unknown> = {}
 
   @Property({ columnType: "jsonb", nullable: true })
-  provider_metadata: Record<string, unknown> | null
+  provider_metadata: Record<string, unknown> | null = null
 
   @BeforeCreate()
   onCreate() {