fix: exclude tools field from agent config spread

[randomm]

Summary

Fixes subagent permission bug where tools field was spread into resolved agent config, causing permission blocks to be ignored for tool availability.

Root Cause

In packages/opencode/src/config/config.ts around line 529, the Agent schema transform spreads the entire agent object:

return { ...agent, options, permission, steps }

This preserves the tools field alongside the new permission field, causing tools to override permission-based tool availability.

The Fix

Destructure to exclude tools before spreading:

const { tools, maxSteps, ...rest } = agent
return { ...rest, options, permission, steps }

Testing

• Built OpenCode from source with this fix
• Verified with opencode debug agent <name>:
  • System v1.0.220: tools field PRESENT (broken)
  • Fixed build: tools field ABSENT (working)
• Subagent permission blocks now properly control tool availability

Fixes #6527 Related to #6873