fix(connect): stable per-tab relay session id — re-attach auto-recovers (#17)

When a tab's chrome.debugger session was torn down and re-established
(cross-process navigation, MV3 service-worker restart wiping the in-memory
maps, DevTools stealing the debugger), the extension minted a brand-new
monotonic `cb-tab-N` for the same tab. The daemon stays bound to the old id and
the relay consumes attach/detach events without telling it to rebind, so the
session was orphaned permanently → `stale sessionId / tab is gone`, and re-open
never recovered.

Derive the session id from the STABLE Chrome tabId (`cb-tab-<tabId>`) instead.
Any re-attach of the same tab now restores the SAME session the daemon already
holds, so eval/snapshot transparently follow the new page after a navigation.
Extension 0.4.3 → 0.4.4. Adds a relay unit test for the detach→reattach-same-
session recovery contract.

cli/src/native/relay.rs

@@ -330,6 +330,45 @@ mod tests {
         }
     }
 
+    #[test]
+    fn reattach_with_same_session_restores_target() {
+        // Issue #17 recovery contract. A tab's chrome.debugger session is torn
+        // down (cross-process nav, SW restart, …) then re-attached. The fix has
+        // the extension reuse the SAME `cb-tab-<tabId>` id across that churn, so
+        // after detach+reattach the relay must expose the NEW target under the
+        // SAME session — which is exactly the session the daemon is still bound
+        // to, so its eval/snapshot auto-follow the new page instead of going stale.
+        let mut s = RelayState::new();
+        s.handle_ext_message(&attached_event("T_old", "cb-tab-42"), "tok");
+        s.handle_ext_message(
+            &json!({
+                "method": "forwardCDPEvent",
+                "params": { "method": "Target.detachedFromTarget", "params": { "sessionId": "cb-tab-42" } }
+            }),
+            "tok",
+        );
+        s.handle_ext_message(&attached_event("T_new", "cb-tab-42"), "tok");
+
+        let route = s.route_client_command(1, &json!({ "id": 1, "method": "Target.getTargets" }));
+        match route {
+            ClientRoute::Local(v) => {
+                let infos = v["result"]["targetInfos"].as_array().unwrap();
+                assert_eq!(infos.len(), 1, "only the new target should remain");
+                assert_eq!(infos[0]["targetId"], "T_new");
+            }
+            _ => panic!("getTargets must be local"),
+        }
+        // The daemon's existing session id still resolves — to the new target.
+        let route = s.route_client_command(
+            1,
+            &json!({ "id": 2, "method": "Target.attachToTarget", "params": { "targetId": "T_new" } }),
+        );
+        assert_eq!(
+            route,
+            ClientRoute::Local(json!({ "id": 2, "result": { "sessionId": "cb-tab-42" } }))
+        );
+    }
+
     #[test]
     fn browser_get_version_is_answered_locally() {
         // Liveness probe must NOT be forwarded (the extension can't do

extensions/ab-connect/background.js

@@ -24,7 +24,6 @@ let port = null
 /** Whether the native-messaging host (the local chrome-use CLI) is linked.
  *  Read by the popup status page. */
 let hostConnected = false
-let nextSession = 1
 /** tabId -> { sessionId, targetId } */
 const tabs = new Map()
 /** sessionId -> tabId (main session per tab) */
@@ -261,7 +260,16 @@ async function attachTab(tabId) {
   const targetInfo = info?.targetInfo
   const targetId = String(targetInfo?.targetId || '')
   if (!targetId) throw new Error('attachTab: no targetId')
-  const sessionId = `cb-tab-${nextSession++}`
+  // Derive the session id from the STABLE Chrome tabId, not a monotonic counter
+  // (issue #17). A tab's chrome.debugger session can be torn down and
+  // re-established — cross-process navigation, a service-worker restart wiping
+  // these in-memory maps, DevTools stealing the debugger — and each time the tab
+  // re-attaches. With a counter, re-attach minted a BRAND-NEW `cb-tab-N`, which
+  // orphaned the daemon's binding (it's still pinned to the old id and the relay
+  // never tells it to rebind) → permanent "stale sessionId / tab is gone". The
+  // tabId is stable across all of that, so `cb-tab-<tabId>` restores the SAME
+  // session the daemon already holds → eval/snapshot auto-follow the new page.
+  const sessionId = `cb-tab-${tabId}`
   const entry = { sessionId, targetId }
   tabs.set(tabId, entry)
   sessionToTab.set(sessionId, tabId)

extensions/ab-connect/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "chrome-use",
-  "version": "0.4.3",
+  "version": "0.4.4",
   "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": {