docs: purge chain-of-thought leakage from prose

Delete design-session citations (decision/audit/plan ordinals, stack
positions), change narration, review choreography, and reviewer-addressed
justification from comments, JSDoc, docs, READMEs, Agent Notes, tests, and
generator templates; restate every affected fact as current-state contract
prose. Fix generated docs at their sources and regenerate the catalogs and
cordis-surface regions; re-paste type-equiv blocks; update every bilingual
counterpart and re-record the pairs. Record the citation rule in the
committed-artifact-citations Agent Note.

docs/user/guide/providers.zh.md

@@ -122,7 +122,7 @@ settings 段落**逐个提供方**地盖在 `cordis.yml` 的同名配置之上
 
 ## 让 agent（智能体）用上新提供方
 
-配好的路由会出现在 Web 的模型选择器里，随时可切，这也是最常用的方式。
+配好的路由会出现在 Web 的模型选择器里，随时可切。
 
 在那里切换同时也就选定了默认值：你选的模型会成为下一个新会话的起点，记录在 `settings.yaml` 的 `agent-default-model` 段里。没有另一个单独的手势。