feat(ui): add advanced controls accordion — inference steps, cfg, infer method, seed, lm cot, schedule, metadata

feat(pipeline): wire cover/extend/edit task_types in studio.generate

feat(backend): apply lora stack before mode dispatch

refactor(pipeline): rewrite for real acestep AceStepHandler+LLMHandler api

feat(backend): add ace-step studio backend with dispatch + zerogpu wrap