赵月辉 / fastgpt-migrated

* perf: reduce workflow variable replacement CPU cost

* doc

* doc

* refactor: move workflow variable replacement to service

* test: cover variable key detection

* refactor: move workflow node params helper

* refactor: remove default llm request params

* fix: stop oversized variable replacement rounds

* fix: stop oversized variable replacement without throwing

* doc

* fix: i18n

* fix: error show

* chore: log oversized string replacement