fix(keyword-detector): start ralph-loop when ulw keyword detected (#3113)

Plain 'ulw' keyword now starts the continuation loop via
ralphLoop.startLoop(), matching README promise. Wired through
create-core-hooks.ts and create-transform-hooks.ts.

TDD: 40 keyword-detector tests pass, 1239 hook tests pass, tsc clean.

Closes #3113

src/plugin/hooks/create-core-hooks.ts

@@ -36,6 +36,7 @@ export function createCoreHooks(args: {
     pluginConfig,
     isHookEnabled: (name) => isHookEnabled(name as HookName),
     safeHookEnabled,
+    ralphLoop: session.ralphLoop,
   })
 
   return {