refactor: give the inferred-return-type public methods on the engine.ts and protocol.ts facades explicit return types (.d.ts unchanged), so the codemod can move their bodies #30054

domain:server#6 · os-support-ai · session_01WGufzibcN9oHa8kDbTTnL5

Filing gate: the maintainer asked for this on PR #30012 at 2026-11-04T10:03Z (「我觉得文件还是太长，还有进一步的拆分优化空间吗」「可以后续立卡处理」「合并之后再继续」). The facades are merged: engine.ts as 237f513 (#30012) and protocol.ts as 48914fd (#29998). Estimates come from the #29986 / #29985 dev reports. ⛔ Not a claim. Triage sets the grade and the lane (devx or server).

Business reason: bodies whose public return type is inferred stay on the class as #30019 exceptions, because moving them would change the .d.ts re-inference. In engine.ts there are 8: registerApp, registerHook, registerDriver, init, triggerHooks, destroy, setDatasourceMapping and getStatus, 491 lines in all. In protocol.ts they include getDiscovery (460), findData (751), getData (75), cloneData (105) and the four *MetaItem doors. Writing each return type explicitly, equal to what is inferred today, lets the codemod move the body.
Reader who acts: packages/objectql / packages/metadata-protocol owners.

What to do

• Spell each return type explicitly, and prove the public .d.ts is byte-equal before and after. That is one PR with no behaviour change.
• Then re-run the codemod so the bodies move, and drop their rows from the tooling: a structural gate that refuses any method body in a facade file once protocol.ts and engine.ts land in facade form (ruling 6624258595) #30019 allow-list.
  Dedupe: inferred return type facade, 30019 exception. New.