feat(api_key): implement API key management with creation, retrieval, and deletion endpoints

thoughts-backend/migration/src/lib.rs

@@ -4,6 +4,7 @@ mod m20240101_000001_init;
 mod m20250905_000001_init;
 mod m20250906_100000_add_profile_fields;
 mod m20250906_130237_add_tags;
+mod m20250906_134056_add_api_keys;
 
 pub struct Migrator;
 
@@ -15,6 +16,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20250905_000001_init::Migration),
             Box::new(m20250906_100000_add_profile_fields::Migration),
             Box::new(m20250906_130237_add_tags::Migration),
+            Box::new(m20250906_134056_add_api_keys::Migration),
         ]
     }
 }