v0.10.0 — archive chat sends and fold archive cards

Archive chat sends and foldable archive cards.

• A successful message sent from the conversation composer is now mirrored into the current workspace archive (origin: "compose"), persisted immediately and de-duplicated by content against every active / archived segment.
• Archive cards gained a fold toggle. Auto-saved chat messages start collapsed; manually archived and notepad-send segments (plus legacy archives) start expanded.
• Added origin metadata (manual / send / compose) to archived segments in .dsh/notepad.json, with forgiving reads for old files.

对话发送自动归档 + 归档卡片可折叠。

• 在会话输入框成功发送消息后，会作为当前工作区的归档分段保存（origin: "compose"），立即落盘，并按内容与所有活动 / 归档分段去重。
• 归档卡片新增折叠按钮：自动保存的对话消息默认折叠；手动归档、记事本发送按钮归档以及旧版归档默认展开。
• .dsh/notepad.json 的归档分段新增 origin（manual / send / compose）字段，旧文件读取时保持兼容。