fix(tmux,run,hooks): the four pre-existing bugs the #37 evaluation found

- tmux targets are exact (`=name`, `=name:` for panes/options): a bare
  `-t agenthub-lane-1` resolves by prefix to agenthub-lane-12 once lane 1
  is gone, so killing a finished lane could kill another.
- getRun/killRun refuse ids that are not `agenthub-lane-<n>`, so
  DELETE /api/run/main can no longer kill a user's own tmux session.
- router/apply reports restart_required only for a running pane; getRun
  returns a `gone` handle, so it was always true.
- needs_action is cleared only by the session that raised it (new nullable
  lanes.needs_action_session); a second session in the same cwd used to
  clear it on its second hook.

server/__tests__/cc-reload.test.js

@@ -43,13 +43,13 @@ function stubTmux(sessions, panes = {}) {
     calls.push(args);
     if (args[0] === "list-sessions") return sessions.join("\n");
     if (args[0] === "has-session") {
-      if (sessions.includes(args[2])) return "";
+      if (sessions.includes(args[2].slice(1))) return "";
       const e = new Error("no such session");
       e.status = 1;
       throw e;
     }
     if (args[0] === "display-message") {
-      const name = args[3];
+      const name = args[3].slice(1, -1);
       const cmd = panes[name] ?? "claude";
       if (cmd === null) {
         const e = new Error("pane gone");
@@ -59,7 +59,7 @@ function stubTmux(sessions, panes = {}) {
       return `${cmd}\n`;
     }
     if (args[0] === "send-keys") {
-      if (panes[args[2]] === "__send-fails__") throw new Error("pane died mid-send");
+      if (panes[args[2].slice(1, -1)] === "__send-fails__") throw new Error("pane died mid-send");
       return "";
     }
     return "";