[codex] fix Cursor Claude session history

[BigStrongSun]

What changed

• Set the WSL Claude wrapper template to use a Windows-visible CLAUDE_CONFIG_DIR.
• Document migration from WSL ~/.claude into C:\Users\sunda\.claude.
• Document the Windows project-key junction needed for Cursor's Sessions view.
• Add validation for the shared session directory.

Why

Cursor's Claude Code extension runs in the Windows extension host and lists sessions from the Windows Claude config path. WSL Claude was writing session JSONL files under /home/openclaw/.claude, so past conversations could disappear from the Cursor plugin after restart even though the underlying Claude sessions still existed.

Validation

• Compiled the C# wrapper template with csc.exe.
• Ran git diff --check.
• Verified no real API token was added to the tracked docs or wrapper template.