feat(relay): group-scoped Target.getTargets — restore follow-popup + cross-session adopt under isolation (#40)

Move multi-agent isolation from blunt daemon-side filtering to relay-side
group scoping, so a session can adopt new tabs again (follow-popup, OAuth
results, cross-session adopt-by-targetId) without ever seeing the user's or
another agent's tabs.

Relay (relay.rs): track client->group (announced via new local ABRelay.setGroup,
or the first createTarget's agentGroup) and target->group (created tabs tagged
from the createTarget reply; an explicit attachToTarget tags the target into the
adopter's group = #21; a pop-up inherits its opener's group via openerTargetId).
Target.getTargets returns ONLY the requesting client's group; a client that never
announced a group (older daemon) gets the full list — fully backward-compatible.
+5 unit tests.

Daemon (browser.rs): announce_group() on connect sets relay_scoped. Adoption in
discover/resync/adopt_newly_opened is re-enabled ONLY when relay_scoped; without
it (launch / real CDP / older relay that didn't answer the announce) the daemon
keeps strict daemon-side isolation. So this can't regress the 125/125 isolation.

Extension (ab-connect 0.4.10): synthesized Target.attachedToTarget targetInfo now
carries openerTargetId (pop-ups inherit opener's group) and abGroup (the tab-group
title, so the relay re-attributes existing tabs after ITS own restart, since
createTarget tagging won't re-run). tabScopeHints().

Back-compat verified live: new daemon + OLD relay -> announce fails ->
relay_scoped=false -> strict fallback, open/eval/url all work. The new extension
(publish to CWS, strip manifest key) activates follow-popup; relay+daemon ship now.
861 tests pass.

cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "chrome-use"
-version = "1.5.21"
+version = "1.5.22"
 edition = "2021"
 description = "Fast browser automation CLI for AI agents"
 license = "Apache-2.0"