[BUG] Team agents don't inherit [1m] context window from parent session

Summary

When spawning teammates via the Task tool in a team context, agents don't inherit the parent session's [1m] context window variant. Standalone Task agents (non-team) inherit correctly.

Reproduction

Parent session running claude-opus-4-6[1m].

Standalone Task agent (works):

Task(subagent_type="general-purpose", prompt="report your model ID")
→ reports claude-opus-4-6[1m] ✓

Team agent (broken):

TeamCreate(team_name="test")
Task(subagent_type="general-purpose", name="test-agent", team_name="test", prompt="report your model ID")
→ reports claude-opus-4-6 (no [1m]) ✗

Neither call sets the model parameter — both should inherit from parent. The standalone agent does, the team agent doesn't.

Expected behavior

Team agents should inherit the parent's [1m] context variant, same as standalone Task agents.

Why it matters

Team agents reading large files (research PDFs, full codebases) benefit from extended context. The current behavior silently downgrades them without any indication.

Environment

• Claude Code v2.1.45
• Model: claude-opus-4-6[1m]
• macOS Darwin 25.3.0