fix(connect): keep native-messaging host as com.agent_browser.connect (no relay break)

Reverting the host-name rename from the chrome-use rebrand. The host name is
invisible internal plumbing (lives only in NativeMessagingHosts/*.json and the
extension), so renaming it to com.leeguoo.chrome_use bought nothing user-facing
but broke the relay for every existing user: the new chrome-use binary couldn't
find a matching host/extension, silently fell back to raw --remote-debugging-port,
and re-popped the 'Allow remote debugging?' consent dialog.

Keeping com.agent_browser.connect means the renamed chrome-use binary keeps
working with the already-installed host json and the live ab-connect 0.4.2
extension — zero relay break, no dialog, and the store republish becomes an
OPTIONAL cosmetic display-name update (manifest bumped 0.5.0 → 0.4.3, name stays
chrome-use). Only the binary/command name changed for users.

extensions/ab-connect/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "chrome-use",
-  "version": "0.5.0",
+  "version": "0.4.3",
   "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": {