feat: add reply functionality to thoughts, including database migration and tests

thoughts-backend/migration/src/lib.rs

@@ -5,6 +5,8 @@ mod m20250905_000001_init;
 mod m20250906_100000_add_profile_fields;
 mod m20250906_130237_add_tags;
 mod m20250906_134056_add_api_keys;
+mod m20250906_145148_add_reply_to_thoughts;
+mod m20250906_145755_add_visibility_to_thoughts;
 
 pub struct Migrator;
 
@@ -17,6 +19,8 @@ impl MigratorTrait for Migrator {
             Box::new(m20250906_100000_add_profile_fields::Migration),
             Box::new(m20250906_130237_add_tags::Migration),
             Box::new(m20250906_134056_add_api_keys::Migration),
+            Box::new(m20250906_145148_add_reply_to_thoughts::Migration),
+            Box::new(m20250906_145755_add_visibility_to_thoughts::Migration),
         ]
     }
 }