docs: add Related sections to plugin and web interface pages

- building-plugins.md, manifest.md: link to architecture, SDK, channel/provider plugins
- control-ui.md, tui.md: link to sibling web interfaces and CLI

docs/plugins/building-plugins.md

@@ -273,3 +273,11 @@ internal imports — never import your own plugin through its SDK path.
     Full manifest schema reference
   </Card>
 </CardGroup>
+
+## Related
+
+- [Plugin Architecture](/plugins/architecture) — internal architecture deep dive
+- [SDK Overview](/plugins/sdk-overview) — Plugin SDK reference
+- [Manifest](/plugins/manifest) — plugin manifest format
+- [Channel Plugins](/plugins/sdk-channel-plugins) — building channel plugins
+- [Provider Plugins](/plugins/sdk-provider-plugins) — building provider plugins

docs/plugins/manifest.md

@@ -276,3 +276,9 @@ See [Configuration reference](/gateway/configuration) for the full `plugins.*` s
 - If your plugin depends on native modules, document the build steps and any
   package-manager allowlist requirements (for example, pnpm `allow-build-scripts`
   - `pnpm rebuild <package>`).
+
+## Related
+
+- [Building Plugins](/plugins/building-plugins) — getting started with plugins
+- [Plugin Architecture](/plugins/architecture) — internal architecture
+- [SDK Overview](/plugins/sdk-overview) — Plugin SDK reference

docs/web/control-ui.md

@@ -276,3 +276,10 @@ Example:
 ```
 
 Remote access setup details: [Remote access](/gateway/remote).
+
+## Related
+
+- [Dashboard](/web/dashboard) — gateway dashboard
+- [WebChat](/web/webchat) — browser-based chat interface
+- [TUI](/web/tui) — terminal user interface
+- [Health Checks](/gateway/health) — gateway health monitoring

docs/web/tui.md

@@ -168,3 +168,8 @@ No output after sending a message:
 - `disconnected`: ensure the Gateway is running and your `--url/--token/--password` are correct.
 - No agents in picker: check `openclaw agents list` and your routing config.
 - Empty session picker: you might be in global scope or have no sessions yet.
+
+## Related
+
+- [Control UI](/web/control-ui) — web-based control interface
+- [CLI Reference](/cli) — full CLI command reference