fix(session): enforce trusted read scope

docs/webui.md

@@ -76,7 +76,7 @@ This path avoids hand-editing `config.json` for normal setup. Use the reference
 | Agent activity | See thinking, tool calls, file edits with diffs, command output, and generated artifacts in context |
 | Workspace | Pick the project workspace before asking for file or shell work |
 | Access | Choose the access mode for local capabilities allowed by your gateway configuration |
-| Composer | Send text, images, voice input, slash commands, and `@` mentions for Apps or MCP presets |
+| Composer | Send text, images, voice input, slash commands, and `@` mentions for topics, Apps, or MCP presets |
 | Channels | Connect and validate chat platforms, install their optional support, and manage saved channel setup |
 | Apps | Install, test, update, and use local CLI App adapters and MCP presets |
 | Skills | Inspect available built-in and workspace skills before relying on them |
@@ -144,8 +144,10 @@ clients.
 
 The composer supports plain messages, image attachments, voice input when
 transcription is configured, slash commands, and `@` mentions for installed Apps
-or MCP presets. The model badge shows the current model or preset and links back
-to model settings when setup is incomplete.
+or MCP presets. Mention another topic to attach a stable reference; nanobot reads
+that topic only when its history is relevant and can link it in the response. The
+model badge shows the current model or preset and links back to model settings
+when setup is incomplete.
 
 For image generation, configure an image provider first and then use the WebUI
 image mode from the composer. See [`image-generation.md`](./image-generation.md)