feat: implement multiple oauth providers in the frontend

internal/assets/migrations/000002_oauth_name.down.sql

@@ -0,0 +1 @@
+ALTER TABLE "sessions" DROP COLUMN "oauth_name";

internal/assets/migrations/000002_oauth_name.up.sql

@@ -0,0 +1,8 @@
+ALTER TABLE "sessions" ADD COLUMN "oauth_name" TEXT;
+
+UPDATE
+    "sessions"
+SET
+    "oauth_name" = "Generic"
+WHERE
+    "oauth_name" IS NULL AND "provider" IS NOT NULL;