fix: separate browser_cdp into its own toolset

browser_cdp_tool.py registers before browser_tool.py (alphabetical
import order), so its stricter check_fn (requires CDP endpoint) becomes
the toolset-level check for all 11 browser tools. This causes
'hermes doctor' to report the entire browser toolset as unavailable
even when agent-browser is correctly installed.

Move browser_cdp to toolset='browser-cdp' so it is evaluated
independently. browser_navigate et al. only need agent-browser;
browser_cdp additionally requires a reachable CDP endpoint.

tools/browser_cdp_tool.py

@@ -402,7 +402,7 @@ def _browser_cdp_check() -> bool:
 
 registry.register(
     name="browser_cdp",
-    toolset="browser",
+    toolset="browser-cdp",
     schema=BROWSER_CDP_SCHEMA,
     handler=lambda args, **kw: browser_cdp(
         method=args.get("method", ""),