Fix Windows settings file path issue in ccr code command

[haikow]

Problem
When running ccr code on Windows, users encounter the error:
Error: Settings file not found: '{env:{ANTHROPIC_AUTH_TOKEN:test,ANTHROPIC_API_KEY:,ANTHROPIC_BASE_URL:http://127.0.0.1:3456,NO_PROXY:127.0.0.1,DISABLE_TELEMETRY:true,DISABLE_COST_WARNINGS:true,API_TIMEOUT_MS:600000}

Closes #862

Root Cause

1. The code was passing a JSON string directly to the --settings parameter instead of a file path
2. The shell-quote library was escaping colons in Windows file paths, causing path corruption
3. String concatenation for spawn command was causing argument parsing issues

Solution

• Create temporary settings file: Generate a real JSON file instead of passing JSON strings
• Fix argument handling: Use proper spawn args array instead of shell-quoted concatenated strings
• Platform compatibility: Maintain shell: true on Windows for PATH resolution
• Resource cleanup: Automatically clean up temporary files on process exit