VS Code 1.136: Copilot Editor Preview Features policy incorrectly hides native Claude Agent Host harness

Does this issue occur when all extensions are disabled?: No

Starting with VS Code 1.136, the Claude harness disappears from the chat harness picker when the signed-in Copilot organization has Editor Preview Features disabled.

The regression appears to be caused by this change:

// 1.135
case "claude": return true;

// 1.136
case "claude":
return getValue("chat.agentHost.claudeAgent.enabled") !== false;

chat.agentHost.claudeAgent.enabled is restricted by the Copilot organization's Editor Preview policy, so a local value of true is ignored.

This unintentionally allows a GitHub Copilot organization policy to disable the native Claude Agent Host harness even when Claude is independently authenticated using Anthropic OAuth / Claude Max.

Expected behavior: the Copilot Editor Preview policy should not disable the independently authenticated Claude harness. Alternatively, if this coupling is intentional, VS Code should clearly indicate that Claude is hidden by organization policy rather than silently removing it from the picker.

This was difficult to diagnose because several independent layers are involved: VS Code, Agent Host, Claude SDK/CLI, Anthropic OAuth, Copilot policy, and local settings.

- VS Code Version: 1.136.1
- OS Version: macOS 15.3.2 (24D81)

Steps to Reproduce:

1. v1.135.0: Claude appears
2. v136.1: Claude hidden - same machine, Claude CLI/extension, OAuth credentials and settings

Compare the Claude harness picker behavior between VS Code 1.135.0 and 1.136.1, focusing on the `chat.agentHost.claudeAgent.enabled` setting and the Copilot Editor Preview policy. Reproduce with Claude authenticated through Anthropic OAuth or Claude Max while that policy is disabled; done means the independently authenticated harness remains available or the policy-driven hiding is clearly identified.

Written by the indexing model from the issue text.