mcp: local tool calls return result: null, response text goes to Logs instead

Description

Summary
MCP local server tools return result: null in the execute runtime; the actual response text is emitted to Logs instead of being available as the tool result. All 42 tools from the same MCP server exhibit the identical behavior.
Environment

• opencode version: 2.0.3
• OS: Windows_NT 10.0.26200 (MINGW64_NT-10.0-26200, win32 x64)
• Terminal: xterm-256color (MINGW64 / Git Bash)
• Shell: /usr/bin/bash (Git Bash), COMSPEC: C:\WINDOWS\system32\cmd.exe
• Install/channel: npm global, latest
• Active plugins: none (all disabled in config)
• MCP server: @cocaxcode/api-testing-mcp@0.13.4 (local, via npx)
• MCP SDK (server side): @modelcontextprotocol/sdk@1.29.0
  Reproduction

1. Configure a local MCP server in opencode.jsonc:
   "api-testing": {
   "type": "local",
   "command": ["npx", "-y", "@cocaxcode/api-testing-mcp@latest"],
   "enabled": true
   }
2. Start opencode, open a session.
3. In a tools code block, call any MCP tool, e.g.:
   const result = await tools["api-testing"].env_list();
   console.log(result); // null
4. Observe the output:
   result: null
   Logs: [ { "name": "local_dev", ... } ]
   Expected Behavior
   result should contain the parsed tool response (the array of environments), matching what the MCP server returns:
   { "content": [{ "type": "text", "text": "[{ "name": "local_dev", ... }]" }] }
   The content[0].text value should be parsed and returned as the tool result, not logged separately.
   Actual Behavior
   Every MCP tool call returns result: null. The actual response text appears under a Logs: heading in the output. This is consistent across all 42 tools from the api-testing MCP server.
   Sample output:
   null

Logs:
[
{
"name": "local_dev",
"active": true,
"default": true,
"group": "rh-front",
"variableCount": 2,
"spec": "rh-remote-v3"
}
]
The MCP server's response format is correct per the MCP protocol — the issue is on the OpenCode client side, which fails to pass content[0].text through as the tool return value.
Additional Context

• The MCP server logs show mcp connected server=api-testing tools=42 — connection and tool registration succeed.
• No errors in ~/.local/share/opencode/log/opencode.log related to MCP.
• All 42 tools (env_list, api_spec_list, api_import, collection_list, etc.) exhibit the same result: null behavior.
• Tool validation errors (wrong argument names/types) DO return proper error messages — only successful calls produce null.
• The MCP server uses @modelcontextprotocol/sdk@1.29.0; OpenCode's bundled MCP client version is unknown but should be compatible.
• Config: opencode.jsonc with "type": "local" MCP, shell "sh", "lsp": false.

Plugins

No response

OpenCode version

v2.0.3

Steps to reproduce

No response

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response