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/context/tmux-context/tests/tmux-context.spec.ts

@@ -138,8 +138,7 @@ async function fire(
 ): Promise<void> {
   const decision = await agentEvents(ctx, agent).waterfall(
     'agent/pre-step',
-    [],
-    { turn, step, signal },
+    { messages: [], turn, step, signal },
     () => Promise.resolve({ kind: 'enter' as const, messages: [] }),
   )
   if (decision.kind === 'enter') {