feat: add events table to schema and update SQL migration script

Backend/drizzle/0002_hesitant_molecule_man.sql

@@ -0,0 +1,7 @@
+CREATE TABLE "events" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"title" varchar(255) NOT NULL,
+	"created_at" timestamp with time zone DEFAULT now() NOT NULL,
+	"video_url" varchar(255) NOT NULL,
+	CONSTRAINT "events_video_url_unique" UNIQUE("video_url")
+);