refactor(db): use new store interface

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

@@ -0,0 +1,10 @@
+ALTER TABLE "sessions" ADD COLUMN "oauth_name" TEXT;
+
+UPDATE "sessions"
+SET "oauth_name" = CASE
+  WHEN LOWER("provider") = 'github' THEN 'GitHub'
+  WHEN LOWER("provider") = 'google' THEN 'Google'
+  ELSE UPPER(SUBSTR("provider", 1, 1)) || SUBSTR("provider", 2)
+END
+WHERE "oauth_name" IS NULL AND "provider" IS NOT NULL;
+