New CLAUDE_CODE_QUESTION_OPTIONAL_DESCRIPTIONS environment variable

What

A new environment variable, CLAUDE_CODE_QUESTION_OPTIONAL_DESCRIPTIONS, makes the descriptions on AskUserQuestion-style options optional instead of required. It only takes effect when CLAUDE_CODE_ENTRYPOINT is one of a fixed set of values (sdk-ts, sdk-py, sdk-cli, local-agent, claude-desktop, claude-desktop-3p) or when the session is remote.

This new variable also acts as an alias for the existing extended-question behavior: setting either CLAUDE_CODE_QUESTION_EXTENDED or CLAUDE_CODE_QUESTION_OPTIONAL_DESCRIPTIONS now turns on that extended AskUserQuestion behavior.

Why

This lets specific integrations (SDKs, local agents, Claude desktop, and remote sessions) skip writing option descriptions for AskUserQuestion prompts when they aren't needed, without affecting other entry points.