v0.11.0 — undo composer inserts / replaces, never replay sends

Record composer inserts / replaces in undo, keep sends irreversible.

• Plugin undo / redo now also records "insert into composer" and "replace composer" as single steps (stored as the draft text before / after the operation), so undo restores the draft the action overwrote and redo applies it again.
• A composer step only applies while the draft still equals the content that step produced; if the draft was typed into, cleared by a send or belongs to another session, the stale step is retired instead of wiping newer text.
• Sends are never undo / redo steps: notepad sends, send-to-new-session and the chat-send archive capture all commit with record: false.
• Cards a send archived (origin send / compose) are pinned to their current body and archived state in every restored snapshot, and re-appended when a snapshot predates them, so undo / redo can neither unarchive, rewrite nor resend them.

撤销 / 重做包含插入、替换，发送不可撤销 / 重做。

• 插件撤销 / 重做现在也记录「插入到输入框」和「替换输入框内容」，各记一步（存操作前后的对话框文本）：撤销会把对话框恢复成操作前的内容，重做再放回。
• 只有对话框仍等于该步留下的内容时这一步才生效；之后手动改过、被发送清空或属于别的会话时，该步自动作废，不会吞掉新输入。
• 发送不进入撤销 / 重做：记事本发送、发送到新会话、对话框发送后的自动归档都用 record: false 提交。
• 被发送归档的分段（origin 为 send / compose）在恢复历史快照时按现内容、现归档状态固定，快照里没有就补回，撤销 / 重做既不会恢复成未发送，也不会改写或重发。