feat: add OmniBMS docs to hub

Mirror daelon/OmniBMS (main), local index.md landing page,
nav entry and home page card alongside LC15 and LCGUI.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/index.md

@@ -18,6 +18,12 @@ Welcome to the documentation hub of Daelon Engineering UG.
 
     [:octicons-arrow-right-24: Documentation](lcgui/)
 
+-   :material-battery-charging: **[OmniBMS](omnibms/)**
+
+    Battery management system.
+
+    [:octicons-arrow-right-24: Documentation](omnibms/)
+
 </div>
 
 ## How this site is built

docs/omnibms/index.md

@@ -0,0 +1,11 @@
+# OmniBMS
+
+Battery management system documentation for the Daelon OmniBMS project.
+
+## Documents
+
+| Document | Description |
+|----------|-------------|
+| [Specification](OmniBMS_Spec.md) | System specification |
+| [Implementation Plan](OmniBMS_Umsetzungsplan.md) | Implementation roadmap |
+| [Phase 1 Sprint 1 Kickoff](Phase1_Sprint1_Kickoff.md) | Sprint 1 kickoff notes |

mkdocs.yml

@@ -53,6 +53,7 @@ nav:
   - Home: index.md
   - LiquidCore15: '!import https://git.daelon.cloud/daelon/LiquidCore15?branch=main'
   - LCGUI: '!import https://git.daelon.cloud/daelon/LCGUI?branch=master'
+  - OmniBMS: '!import https://git.daelon.cloud/daelon/OmniBMS?branch=main'
 
 markdown_extensions:
   - admonition