claude-haiku-4.5 sub-agent fails with reasoning effort 'medium' not supported

Bug Report

Description

When the CLI internally routes sub-agent tasks to claude-haiku-4.5, it applies a medium reasoning effort, which is not supported by that model. This causes the following error:

Execution failed: Error: Reasoning effort 'medium' is not supported for model 'claude-haiku-4.5'

Steps to Reproduce

The error occurs during normal CLI usage when the task/explore sub-agent system selects claude-haiku-4.5 as the model with medium reasoning effort applied.

Expected Behavior

The CLI should not assign a reasoning effort level that is incompatible with the selected model. Either:

• Do not set reasoning effort for models that don't support it (e.g., claude-haiku-4.5)
• Map medium to a compatible default for claude-haiku-4.5
• Validate model/reasoning-effort compatibility before dispatch

Environment

• CLI Version: 1.0.79
• Model (main session): gpt-5.4
• Failing sub-agent model: claude-haiku-4.5
• OS: Linux

Beginne im in dem Bericht beschriebenen Task-/Explore-Sub-Agent-Routing- und Modellauswahlpfad der CLI, in dem claude-haiku-4.5 die reasoning effort erhält. Prüfe, wie die Kompatibilität von Modell und effort gehandhabt wird; fertig ist die Änderung, wenn die normale CLI-Nutzung für dieses Modell keine nicht unterstützte Einstellung medium mehr weiterleitet, einschließlich einer Regression-Prüfung, falls die relevante Teststelle gefunden wird.