[Bug] AskUserQuestion tool fails in VS Code panel webview with "Tool result missing due to internal error"

Bug Description
Title AskUserQuestion fails with "Tool result missing due to internal error" in VS Code panel webview (works in terminal TUI) Body ### Summary AskUserQuestion never returns in the VS Code extension panel — every call fails with "Tool result missing due to internal error." The identical tool call renders and works correctly when claude is run in a plain terminal (TUI selector). So the CLI/agent/tool are fine; the failure is isolated to the panel webview component. ### Environment - Claude Code CLI: 2.1.197 - VS Code extension: anthropic.claude-code 2.1.197 (darwin-arm64) - VS Code: 1.126.0 - macOS: Darwin 25.5.0 (Apple Silicon, M5) - Entrypoint: claude-vscode ### Repro 1. In the VS Code panel, trigger any AskUserQuestion (e.g. ask the model to pose a test question). 2. The picker never renders; the tool result comes back as "[Tool result missing due to internal error]". Deterministic, every time. ### Works vs fails - ✅ Same prompt via claude in an external terminal → AskUserQuestion renders as a TUI list and returns the selection normally. - ❌ VS Code panel webview → always "Tool result missing due to internal error." - Normal tools (Bash/Read/Edit) and the chat webview itself work fine — only the interactive AskUserQuestion component fails. ### Already ruled out (none fixed it) - Stale IDE lock files in ~/.claude/ide — cleaned. - Zombie extension host — full Cmd+Q quit, confirmed fresh ext-host pid. - Corrupted install — code --uninstall-extension + rm extension dir + reinstall (same 2.1.197). - Stale webview cache — removed Service Worker CacheStorage/ScriptCache, CachedData, GPUCache. - Account/CLI/tool itself — proven working in terminal. ### Webview console (only Claude-related error observed) Error: Trying to add a disposable to a DisposableStore that has already been disposed of. at i.add (extensionHostProcess.js) via jg.doCreateOutputChannel (May be a red herring triggered by opening DevTools; included for completeness. The GitHub 404s / Copilot lines in console are unrelated.) ### Impact Interactive prompts unusable in the panel. Workaround: run claude in a terminal.

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 2.1.197
• Feedback ID: d3c9eccc-d9f3-4b11-a54c-cb62565aefbf

Errors

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