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.

cli/src/connect.rs

@@ -17,7 +17,7 @@ use std::path::PathBuf;
 
 /// Native-messaging host name; must match `HOST_NAME` in the extension and the
 /// manifest filename.
-pub const HOST_NAME: &str = "com.leeguoo.chrome_use";
+pub const HOST_NAME: &str = "com.agent_browser.connect";
 
 /// Stable id of the `ab-connect` extension, pinned by the `key` in its
 /// manifest.json (and the signing key of the published `.crx`). Chrome only lets