v0.2.0

⚠ BREAKING CHANGES

• channel: remove redundant wechatAllowedUsers config
• channel: rename the JSON key channelProxyScript -> channelNetworkScript
  and update the script's return statement to wrap the URL in an object:
  return 'http://...' becomes return { proxy: 'http://...' }.
• channel: make channelProxyScript loader strict on malformed input
• channel: the telegramProxy config field is removed. Users on a
  proxy must add a channelProxyScript pointing to a TS file that returns
  the proxy URL for 'telegram' (and optionally 'wechat'). See
  docs/requirements.md § 3.6 for the contract.
• Chat log format now uses emoji headers instead of Obsidian-style callouts

Replace > [!type] label timestamp format with simpler {emoji} label timestamp format:

• 💬 for input messages
• ✅ for successful output
• ❌ for errors
• ⚠️ for warnings/permission denials
• 📝 for notes/state info

Changes:

• Update buildCalloutHeader() to use emoji prefix instead of Obsidian syntax
• Update formatPermissionDenials() to use emoji (📝) instead of > [!NOTE]
• Remove duplicate calloutEmoji() implementation from messaging.ts
• Update Telegram HTML converters to match emoji format using string matching
• Update all test assertions to expect emoji format
• Update documentation (requirements.md, CLAUDE.md) with new format examples

The new format is more universally readable and matches what Telegram users already see.
Old chat files with > [!type] format will not be automatically converted.