feat: add parameter preprocessing audit trail

apps/api/migrations/0033_task_param_preprocessing_logs.sql

@@ -0,0 +1,30 @@
+CREATE TABLE IF NOT EXISTS gateway_task_param_preprocessing_logs (
+  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  task_id uuid NOT NULL REFERENCES gateway_tasks(id) ON DELETE CASCADE,
+  attempt_id uuid REFERENCES gateway_task_attempts(id) ON DELETE SET NULL,
+  attempt_no integer,
+  model_type text NOT NULL DEFAULT '',
+  platform_id uuid REFERENCES integration_platforms(id) ON DELETE SET NULL,
+  platform_model_id uuid REFERENCES platform_models(id) ON DELETE SET NULL,
+  client_id text,
+  changed boolean NOT NULL DEFAULT false,
+  change_count integer NOT NULL DEFAULT 0,
+  actual_input jsonb NOT NULL DEFAULT '{}'::jsonb,
+  converted_output jsonb NOT NULL DEFAULT '{}'::jsonb,
+  changes jsonb NOT NULL DEFAULT '[]'::jsonb,
+  model_snapshot jsonb NOT NULL DEFAULT '{}'::jsonb,
+  created_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_gateway_task_param_pre_logs_task
+  ON gateway_task_param_preprocessing_logs(task_id, created_at);
+
+CREATE INDEX IF NOT EXISTS idx_gateway_task_param_pre_logs_attempt
+  ON gateway_task_param_preprocessing_logs(attempt_id)
+  WHERE attempt_id IS NOT NULL;
+
+CREATE INDEX IF NOT EXISTS idx_gateway_task_param_pre_logs_changed
+  ON gateway_task_param_preprocessing_logs(changed, created_at DESC);
+
+CREATE INDEX IF NOT EXISTS idx_gateway_task_param_pre_logs_changes
+  ON gateway_task_param_preprocessing_logs USING gin(changes);