fix: v2.5.7 — panes work on psmux, the Windows tmux

psmux (the WinGet `tmux` on Windows) has no `=name` exact-match targets: it
answered "no server running on session '=agenthub-lane-1'" for a live pane,
so every Windows start reported "the session's command exited as soon as it
started" while the session ran on, and the browser could not attach.

- server/lib/tmux.js: `session`/`pane` targets probe the first live session
  once — `=name` failing where the bare name answers means bare names from
  then on; real tmux keeps `=name` / `=name:` (it matches by prefix otherwise)
- pty-attach.js and cc-update-all-helper.js use the same targets

scripts/cc-update-all-helper.js

@@ -29,6 +29,8 @@ const path = require("path");
 const { execFileSync, spawnSync } = require("child_process");
 // What a failed command printed — plugin-bootstrap.js says why on STDOUT.
 const { failureText } = require("./plugin-update-helper");
+// psmux (the Windows `tmux`) has no `=name:` targets; tmux.js knows which form.
+const { pane: paneTarget } = require("../server/lib/tmux");
 
 const [, , runtimeDirArg, planJson] = process.argv;
 
@@ -170,7 +172,7 @@ function reloadPanes() {
     try {
       paneCmd = execFileSync(
         "tmux",
-        ["display-message", "-p", "-t", `=${name}:`, "#{pane_current_command}"],
+        ["display-message", "-p", "-t", paneTarget(name), "#{pane_current_command}"],
         { encoding: "utf8", timeout: 15_000, stdio: ["ignore", "pipe", "pipe"] }
       ).trim();
     } catch {
@@ -190,8 +192,10 @@ function reloadPanes() {
         // Atomics.wait, not `sleep`: Windows has no sleep binary.
         if (!first) Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0, 1000);
         first = false;
-        execFileSync("tmux", ["send-keys", "-t", `=${name}:`, "-l", command], { timeout: 15_000 });
-        execFileSync("tmux", ["send-keys", "-t", `=${name}:`, "Enter"], { timeout: 15_000 });
+        execFileSync("tmux", ["send-keys", "-t", paneTarget(name), "-l", command], {
+          timeout: 15_000,
+        });
+        execFileSync("tmux", ["send-keys", "-t", paneTarget(name), "Enter"], { timeout: 15_000 });
       }
       reloaded.push(name);
     } catch {