gws gmail +send incorrectly encodes non-ASCII subject lines

[mobiusclaw-stack]

• When sending emails with Chinese characters in the subject using gws gmail +send, the subject line appears garbled in Gmail (e.g., "新世紀網每日摘要" shows as "新世紀網毠日æÂ'˜è¦Â")
• Same issue occurs when using the raw API with base64 encoded messages
• The issue does not occur with gog CLI which handles encoding correctly
• gws version: 0.3.4

[jpoehnelt]

fixed in #322