fix(ab-connect): transparently re-attach a stale cb-tab session before failing (0.4.6, #20.1)

When a tab navigates across render processes (e.g. an SSO redirect to another
origin like login.account.rakuten.com), the debugger handle detaches and the
session drops out of the relay maps, so the next command dead-ends with
'stale sessionId ... its tab is gone' — even open/navigate, which should always
be able to drive the tab. But cb-tab-<tabId> encodes the STABLE Chrome tabId
(#17), and the tab itself usually survives the nav.

So before throwing, recoverSessionTab() parses the tabId out of the session,
checks the tab still exists + is eligible, and re-attaches (attachTab re-mints
the identical cb-tab-<tabId> session, keeping the daemon's binding valid), then
the in-flight command retries against the recovered tab. Complements the 0.4.5
onDetach proactive re-attach: that heals on the detach event, this heals lazily
on the next command if the event was missed. Falls back to the original error
only when the tab is genuinely gone (closed/restricted).

extensions/ab-connect/background.js

@@ -149,6 +149,25 @@ function tabForTarget(targetId) {
   return null
 }
 
+// Best-effort recovery for a stale `cb-tab-<tabId>` session: the handle is gone
+// from our maps, but if the underlying Chrome tab still exists and is eligible,
+// re-attach to it and return its id so the in-flight command can be retried.
+// Returns null when the tab is genuinely gone (closed / restricted), in which
+// case the caller surfaces the stale-session error. (issue #20.1)
+async function recoverSessionTab(sessionId) {
+  const m = /^cb-tab-(\d+)$/.exec(sessionId)
+  if (!m) return null
+  const tabId = Number(m[1])
+  const tab = await chrome.tabs.get(tabId).catch(() => null)
+  if (!eligible(tab)) return null
+  try {
+    await attachTab(tabId)
+  } catch {
+    return null
+  }
+  return tabs.has(tabId) ? tabId : null
+}
+
 function anyConnectedTab() {
   const it = tabs.keys().next()
   return it.done ? null : it.value
@@ -209,11 +228,22 @@ async function handleForwardCdpCommand(msg) {
   if (sessionId) {
     tabId = tabForSession(sessionId)
     if (!tabId) {
-      throw new Error(
-        `stale sessionId ${sessionId} for ${method}: its tab is gone (closed, ` +
-          `navigated across processes, or lost after an extension restart). ` +
-          `Re-attach by re-opening your target URL before retrying.`,
-      )
+      // The session's debugger handle is gone, but `cb-tab-<tabId>` encodes the
+      // STABLE Chrome tabId (#17). A cross-process navigation (e.g. an SSO
+      // redirect to another origin), a service-worker restart, or DevTools
+      // briefly stealing the debugger all tear the handle down while the tab
+      // itself lives on. Before failing, try to transparently re-attach to that
+      // same tab and retry — so `open`/`navigate`/`eval` self-heal instead of
+      // dead-ending the agent (issue #20.1). attachTab re-mints the identical
+      // `cb-tab-<tabId>` session, so the daemon's binding stays valid.
+      tabId = await recoverSessionTab(sessionId)
+      if (!tabId) {
+        throw new Error(
+          `stale sessionId ${sessionId} for ${method}: its tab is gone (closed, ` +
+            `navigated across processes, or lost after an extension restart). ` +
+            `Re-attach by re-opening your target URL before retrying.`,
+        )
+      }
     }
   } else if (typeof params?.targetId === 'string') {
     tabId = tabForTarget(params.targetId)

extensions/ab-connect/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "chrome-use",
-  "version": "0.4.5",
+  "version": "0.4.6",
   "description": "Let chrome-use drive your logged-in Chrome \u2014 install once, no token, no per-use confirmation.",
   "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA6vQIyscGIPYPZdSpPwPL0+0gxUROyRgCpmvCSDoc8XUm4qm97VbKnD9Ijc1lV22lNWZtE78gaRjt6BeSfuMgnBymnhLKjN1gU6AI5QUU0mrJyeHdWKvrKQR5FmsM2A7Xr1ykE2SiiS8zNUS3Y/6O5l+Nva7wrVy6E4a2dkBVQkOsu+DV+nEZvhIyuDY5D5SPXqNwUTWTaglwj5mjvHz36xSwCWlPmrtJ+ED0AUyrb2z4GIOmvk4kqtBVrh/UD058klLo4CkYOnIybB5aV6WYuwarfPY4bF/dLggPem+ewLNTUNBuwrxj/A4nUv0LJTuRO8rR7f8WR9qnRCY0Ic5saQIDAQAB",
   "icons": {