Add editable Samba global configuration with net conf setparm

Backend:
- Use 'net conf setparm' to update individual parameters
- Accept dictionary of key-value pairs in API

Frontend:
- Add Edit/Cancel/Save buttons to Samba Config tab
- Inline editing of configuration values
- Save changes back to registry

Changes are applied immediately via net conf setparm.

Co-Authored-By: Patrick <patrick@perlbach24.de>

backend/routers/shares.py

@@ -38,7 +38,7 @@ class CreateNFSShareRequest(BaseModel):
 
 
 class SambaConfigRequest(BaseModel):
-    config: str
+    parameters: dict[str, str]
 
 
 class SambaImportRequest(BaseModel):
@@ -108,9 +108,9 @@ async def set_samba_config(
     request: SambaConfigRequest,
     current_user: str = Depends(get_current_user)
 ):
-    """Update Samba global configuration"""
+    """Update Samba global configuration parameters"""
     try:
-        success = share_manager.set_samba_global_config(request.config)
+        success = share_manager.set_samba_global_config(request.parameters)
         if not success:
             raise HTTPException(status_code=400, detail="Failed to update Samba configuration")
         return {"status": "updated"}