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/core/agent-loop/tests/request-cache.e2e.ts

@@ -59,7 +59,7 @@ async function loopHarness(): Promise<Context> {
 
 function waitForIdle(context: Context, agent: Agent): Promise<void> {
   return new Promise((resolve) => {
-    const dispose = context.on('agent/status', (subject, status) => {
+    const dispose = context.on('agent/status', ({ agent: subject, status }) => {
       if (subject === agent && status === 'idle') {
         dispose()
         resolve()