fix(ab-connect): recover a churned-tabId session by stable CDP targetId (0.4.9, #24)

Live-reproduced #24 on 0.4.8 driving the Mercari signin token-exchange hop
(login.jp.mercari.com): the cross-process nav gives the tab a NEW Chrome tabId
while the CDP targetId stays the same. So cb-tab-<oldTabId> can't be recovered —
recoverSessionTab parsed the old tabId, chrome.tabs.get(oldTabId) failed (gone),
and it gave up → permanent 'stale sessionId ... its tab is gone' until the page
settled ~6s later and something re-attached. current/tab <targetId>/daemon
restart all failed because the relay still mapped the targetId to the dead
session.

Fix: remember each session's targetId across detach (sessionTargets map). When
recoverSessionTab can't recover by the encoded tabId, fall back to the STABLE
targetId — chrome.debugger.getTargets() to find the tab now hosting that target,
attach it, and ALIAS the dead cb-tab-<oldTabId> session to the live tab so the
daemon's session id keeps resolving. Longer retry window (~6s) since this hop
takes seconds to settle. Builds on 0.4.6/0.4.8 reattach; covers the tabId-churn
case those missed.

Needs dogfood on the real Mercari flow (can't repro the tabId churn synthetically).

extensions/ab-connect/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "chrome-use",
-  "version": "0.4.8",
+  "version": "0.4.9",
   "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": {