docs: clarify separation of multiplayer and sysadmin plugins

- Updated documentation to emphasize the distinct functionalities of `FFM.Plugin.Multiplayer` (networking/sync) and `FFM.Plugin.Sysadmin` (UI modernization/settings).
- Enhanced descriptions in relevant files to prevent confusion between the two plugins and their purposes.
- Added notes in the multiplayer hub to clearly state that sysadmin and web UI features are separate topics.

This commit improves clarity in the documentation regarding plugin functionalities.

docs/plugins/ffm-plugin-multiplayer.md

@@ -7,7 +7,7 @@ sidebar_label: FFM.Plugin.Multiplayer
 
 ## Purpose
 
-Contains standalone multiplayer-oriented plugin functionality.
+Contains **multiplayer / networking** runtime (bridge, sync). **Not** the same as [FFM.Plugin.Sysadmin](./ffm-plugin-sysadmin) (UI modernization and settings) — keep those mental models separate.
 
 ## Sources
 

docs/plugins/ffm-plugin-sysadmin.md

@@ -7,7 +7,7 @@ sidebar_label: FFM.Plugin.Sysadmin
 
 ## Purpose
 
-Contains system-administration oriented standalone plugin features.
+Contains **sysadmin-oriented UI** features (Unity UI modernization, mod settings menu bridge). **Not** related to [FFM.Plugin.Multiplayer](./ffm-plugin-multiplayer) — multiplayer networking is a separate plugin and concern.
 
 ## Sources
 

docs/plugins/index.md

@@ -10,6 +10,8 @@ These **plugins** ship as `FFM.Plugin.*` assemblies and extend the **framework r
 
 Gameplay mods (`FMF.*`) are documented under **[Mods](../mods/index)** — not here.
 
+**Separation of concerns:** `FFM.Plugin.Multiplayer` (networking / sync / P2P stack) and `FFM.Plugin.Sysadmin` (in-game UI modernization, mod settings menu bridge) are **different products** — do not treat them as one “admin + multiplayer” feature. `FFM.Plugin.WebUIBridge` is likewise **UI shell** (DC2 web UI), not multiplayer.
+
 ## Plugins
 
 - [FFM.Plugin.AssetExporter](./ffm-plugin-asset-exporter)