feat: Add seed_test_data script to populate initial test data for events, testimonials, hackathons, and mentors

imphnen-backend/src/bin/seeder.rs

@@ -23,6 +23,7 @@ fn main() -> Result<(), Box<dyn Error>> {
 	run_seed("seed_hackathons")?;
 	run_seed("seed_gacha_rolls")?;
 	run_seed("seed_mentor_user")?;
+	run_seed("seed_test_data")?;
 	println!("\n✅ All seeding completed successfully.");
 	Ok(())
 }