Context
PR #48578 fixes the most common case (UTF-8 misread as Latin-1) for Feishu Chinese filenames. However, as noted by @Artyomkun, a proper architectural solution should handle multiple encodings (Shift-JIS, EUC-KR, GB18030, etc.) across all channel adapters.
Proposal
Create a central filename utility that:
- Parses Content-Disposition headers with RFC 5987 support
- Detects and recovers common encoding mismatches
- Can be reused by all channel adapters (Feishu, Telegram, Discord, etc.)
Follow-up from #48388 / #48578.
Context
PR #48578 fixes the most common case (UTF-8 misread as Latin-1) for Feishu Chinese filenames. However, as noted by @Artyomkun, a proper architectural solution should handle multiple encodings (Shift-JIS, EUC-KR, GB18030, etc.) across all channel adapters.
Proposal
Create a central filename utility that:
Follow-up from #48388 / #48578.