refactor(agent): unify agent-scoped event signatures as payload objects

All agent/* and agent-loop/config-start-failed events take one payload
object carrying the agent subject; waterfall/serial payloads require a
signal and keep next as the final argument. PreStepContext and
RequestFailureContext are unfolded into payloads and retired.
goal/changed follows the same shape so agentEvents keeps its listener
error containment. ReactLoopAgent builds its scope carrier once in the
constructor. Regenerates scope resolvers, tool-cordis api catalog, and
docs catalogs; updates all affected listeners, tests, and the
core-data-structures docs (en + zh).

packages/guard/repeat-tool-guard/src/index.ts

@@ -223,7 +223,7 @@ export function apply(ctx: Context, config: Config): void {
   // A user interjection changes the context; repetition across it is not a
   // loop. Pure reset hook: always delegates (attaching nothing, vetoing
   // nothing).
-  ctx.on('agent/pre-step', (agent, messages, _context, next): Promise<PreStepDecision> => {
+  ctx.on('agent/pre-step', ({ agent, messages }, next): Promise<PreStepDecision> => {
     if (messages.some(message => message.source.kind === 'user')) chains.delete(agent)
     return next()
   })