Compaction fails with Bedrock: toolConfig not included when conversation has tool history #10259

Description

When using OpenCode with AWS Bedrock (via custom provider or Portkey gateway), compaction fails with:

bedrock error: The toolConfig field must be defined when using toolUse and toolResult content blocks.

Root Cause

When OpenCode performs compaction, it sends the conversation history (which contains tool_calls and tool role messages) but does not include the tools array in the request.

AWS Bedrock's Converse API requires toolConfig to be present whenever the message history contains toolUse or toolResult content blocks.

Reproduction

1. Configure OpenCode with a Bedrock-backed provider (direct or via Portkey/proxy)
2. Have a conversation that uses tools (file edits, bash commands, etc.)
3. Trigger compaction (manual or auto when context fills)
4. Error occurs

Verified via direct API testing

Works (tools array included):

curl -X POST https://api-gateway/v1/chat/completions \
  -d '{
    "model": "us.anthropic.claude-*",
    "tools": [...],  # <-- Present
    "messages": [
      {"role": "assistant", "tool_calls": [...]},
      {"role": "tool", "content": "..."},
      ...
    ]
  }'

Fails (no tools array, but tool history in messages):

curl -X POST https://api-gateway/v1/chat/completions \
  -d '{
    "model": "us.anthropic.claude-*",
    # No "tools" array
    "messages": [
      {"role": "assistant", "tool_calls": [...]},
      {"role": "tool", "content": "..."},
      ...
    ]
  }'
# Error: toolConfig field must be defined

Suggested Fix

Either:

1. Include tools in compaction requests when conversation history contains tool calls
2. Strip tool call history from messages before compaction (convert to plain text summaries)
3. Add empty tools array "tools": [] to satisfy Bedrock's requirement

Environment

• OpenCode version: latest
• Provider: Custom Bedrock via Portkey (@ai-sdk/openai-compatible)
• Model: us.anthropic.claude-opus-4-5-20251101-v1:0
• Config:

{
  "provider": {
    "portkey": {
      "npm": "@ai-sdk/openai-compatible",
      "options": {
        "baseURL": "https://portkey-gateway/v1"
      },
      "models": {
        "us.anthropic.claude-opus-4-5-20251101-v1:0": {
          "modalities": {"input": ["text", "image"], "output": ["text"]},
          "tool_call": true
        }
      }
    }
  }
}

Workaround

Disable auto-compaction and manually start new sessions:

{
  "compaction": {
    "auto": false,
    "prune": true
  }
}