v0.12.0 — edge-only arrow jumps and live sidebar badges

Switch cards from the text edges; refresh sidebar badges on save.

• Arrow keys used to leave a segment from its first / last logical line, so a caret anywhere on the first line (or the first column of the last line, or any row of a soft-wrapped line) jumped to a neighbour card.
• ↑ now leaves the card only at the very start of the text and ↓ only at the very end; a multi-line card keeps its arrows for its own caret, including the middle columns of its first / last line.
• The sidebar unsent badge stayed stale for the current workspace whenever the counts response carried a differently spelled path: the Workspace id is now resolved from the Session's Workspace membership first (then a case-insensitive projection / registry path match).
• The live note count overrides the polled value for that row, and a finished save wakes every mounted view's badge refresh instead of waiting for the poll (now 15s as a backstop for outside edits).

方向键只在分段文本最开头 / 最末尾切换相邻分段；侧边栏工作区角标随当前笔记实时更新。

• 以前按「首行 / 末行」判断，光标在首行任意列、末行第一列，或长文本软换行出来的行上都会误跳到相邻分段。
• 现在只有光标在文本最开头时 ↑ 才跳到上一段末尾、在文本最末尾时 ↓ 才跳到下一段开头；多行分段内部（含首行 / 末行中间列）正常移动光标。
• 侧边栏未发送角标：工作区 id 先按当前会话的工作区成员关系解析（再退回大小写不敏感的投影 / 注册表路径匹配），当前工作区那一行始终显示笔记里的实时数量。
• 任一会话保存成功后会立刻唤醒其它会话的角标刷新，15 秒轮询只作为外部改动的兜底。