fix default completions

database/migrations/2025_11_13_104322_create_habits_table.php

@@ -17,7 +17,7 @@ return new class extends Migration
             $table->text('description');
             $table->integer('target_count');
             $table->integer('current_count');
-            $table->jsonb('completions')->default('[]');
+            $table->jsonb('completions');
             $table->boolean('is_completed')->default(false);
             $table->timestamps();
         });