feat: add mcp_shttp_servers override to conversation initialization (#10171)

Co-authored-by: openhands <openhands@all-hands.dev>

openhands/core/config/mcp_config.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 import re
 import shlex
@@ -302,6 +304,13 @@ class MCPConfig(BaseModel):
             raise ValueError(f'Invalid MCP configuration: {e}')
         return mcp_mapping
 
+    def merge(self, other: MCPConfig):
+        return MCPConfig(
+            sse_servers=self.sse_servers + other.sse_servers,
+            stdio_servers=self.stdio_servers + other.stdio_servers,
+            shttp_servers=self.shttp_servers + other.shttp_servers,
+        )
+
 
 class OpenHandsMCPConfig:
     @staticmethod