Merge remote-tracking branch 'origin/master' into xjt/generated-docs-zh-translation-apply

# Conflicts:
#	.agents/notes/implemented/feature/2026-08-07-default-model-follows-the-picker.i18n.yaml
#	.agents/notes/implemented/feature/2026-08-07-default-model-follows-the-picker.zh.md
#	docs/architecture.i18n.yaml
#	docs/architecture.zh.md
#	docs/user/guide/providers.i18n.yaml
#	docs/user/guide/providers.zh.md
#	docs/user/guide/quickstart.i18n.yaml
#	docs/user/guide/quickstart.zh.md
#	packages/boot/app-boot/README.i18n.yaml
#	packages/boot/app-boot/README.zh.md
#	packages/bundle/headless/README.i18n.yaml
#	packages/bundle/headless/README.zh.md

docs/architecture.zh.md

@@ -17,6 +17,7 @@
 | `ctx.systemPrompt` | `dsh-system-prompt` | 有序的提示词片段、工具 schema 和变量 |
 | `ctx.tools` | `dsh-tools` | 工具注册表和[执行流水线](tool-execution-pipeline.md) |
 | `ctx.agents` | `dsh-agent` | 活跃 agent（智能体）、委托创建、`agent/*` 事件、进程内发起方作用域 |
+| `ctx.agentDefaultModel` | [`dsh-agent-default-model`](../packages/core/agent-default-model/README.md) | 由 Settings 支撑、供 Agent 入口共享的模型选择 |
 | `ctx.agentLoop` | `dsh-agent-loop` | 具体 `Agent` 驱动器 |
 
 ### 能力服务