Multi-MCP server chat configuration

This release adds an mcps config option that connects a single chat to multiple MCP servers, merging and namespacing tools so identical names do not collide.

Features

• Multi-MCP server support in chat config #2736  - Adds an mcps config option that connects a single chat to multiple MCP servers. Tools across servers are merged and namespaced as <name>__<tool> so identical names do not collide; each entry can pin its own environment slug. When set, mcps takes precedence over the existing single-server mcp option, which continues to work unchanged. (Author: @danielkov )

Bug fixes

• Drop tool calls missing toolCallId #2736  - Drops persisted tool calls that arrive without a toolCallId instead of giving them an empty-string id. Previously two such parts in the same restored thread would alias under the same key and the runtime would throw “Tool call argsText can only be appended, not updated” while loading the chat. (Author: @danielkov )