Merge remote-tracking branch 'origin/master' into codex/skill-system

# Conflicts:
#	docs/event-producer-consumer.md
#	docs/module-graph.md
#	docs/rfc/README.md
#	packages/core/agent-core/package.json
#	packages/core/agent-core/src/index.ts
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/index.ts
#	packages/ui/acp-agent/src/index.ts
#	packages/ui/acp-agent/tests/acp-agent.spec.ts
#	packages/ui/stdio-agent/README.md
#	packages/ui/stdio-agent/src/index.ts
#	packages/ui/stdio-agent/tests/stdio-agent.spec.ts

examples/echo-agent/cordis.yml

@@ -33,6 +33,6 @@
   name: '@deepseek-ai/dsh-stdio-agent'
   config:
     model: mock-echo
-    systemPrompt: 'You are echo-agent, a demo agent.'
+    persona: 'You are echo-agent, a demo agent.'
     welcome: 'echo-agent ready. Type a message ("echo <text>" triggers the tool).'
     persistenceRoot: './.sessions'