Team/subagent agents don't inherit Bedrock model identifiers

Description

When running Claude Code with Bedrock (CLAUDE_CODE_USE_BEDROCK=true), spawned team agents (via the Task tool) do not inherit the configured Bedrock model identifier. This causes repeated failures as agents attempt to use model IDs that Bedrock doesn't recognize.

Configuration

{
  "env": {
    "CLAUDE_CODE_USE_BEDROCK": "true",
    "CLAUDE_CODE_SUBAGENT_MODEL": "us.anthropic.claude-opus-4-6-v1",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "us.anthropic.claude-opus-4-6-v1"
  },
  "model": "us.anthropic.claude-opus-4-6-v1"
}

Current Behavior

• The Task tool's model parameter only accepts abstract names: "opus", "sonnet", "haiku"
• "opus" resolves to claude-opus-4-6, which is not a valid Bedrock model ID
• CLAUDE_CODE_SUBAGENT_MODEL and the model field in settings.json are ignored when spawning team agents
• Team agents fail to start or cycle through idle states because Bedrock rejects the resolved model ID
• The only workaround is to manually update the model inside each spawned team agent's session

Expected Behavior

• Spawned team/subagent agents should inherit the Bedrock-compatible model ID from CLAUDE_CODE_SUBAGENT_MODEL, model in settings.json, or the parent session's model
• When CLAUDE_CODE_USE_BEDROCK=true, abstract model names ("opus", etc.) should resolve to valid Bedrock model IDs (e.g., us.anthropic.claude-opus-4-6-v1)

Environment

• Platform: macOS (Darwin 24.6.0)
• Claude Code with Bedrock integration
• Agent teams enabled via CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1