refactor(cli): route /browser subcommands through a dispatch table (#116914)

The 5-branch if/elif ladder in CLICommandsMixin._handle_browser_command
becomes a _BROWSER_SUBCOMMANDS word -> handler table; adding a subcommand
is one row plus a usage line. Subcommand word is case-insensitive, the
argument keeps its case (CDP URL paths are case-sensitive).

hermes_cli/cli_commands_mixin.py

@@ -606,6 +606,16 @@ def _browser_status() -> None:
                "   /browser disconnect   — revert to default")
 
 
+# /browser subcommand word → handler(cli, rest); ``rest`` is the raw (case-preserved)
+# remainder of the line. Adding a subcommand is one row here plus a usage line.
+_BROWSER_SUBCOMMANDS = {
+    "use": lambda cli, rest: _browser_use(cli, rest.lower() or "on"),
+    "connect": lambda cli, rest: _browser_connect(cli, rest or DEFAULT_BROWSER_CDP_URL),
+    "disconnect": lambda cli, rest: _browser_disconnect(cli),
+    "status": lambda cli, rest: _browser_status(),
+}
+
+
 class CLICommandsMixin:
     """Mixin holding the interactive-CLI slash-command handlers."""
 
@@ -2150,24 +2160,21 @@ class CLICommandsMixin:
 
     def _handle_browser_command(self, cmd: str):
         """Handle /browser connect|disconnect|status|use — manage the live Chromium-family CDP connection."""
-        sub = _command_arg(cmd).lower() or "status"
-        if sub == "use" or sub.startswith("use "):
-            _browser_use(self, sub.split(None, 1)[1].strip() if " " in sub else "on")
-        elif sub.startswith("connect"):
-            connect_parts = cmd.strip().split(None, 2)  # ["/browser", "connect", "ws://..."]
-            url = connect_parts[2].strip() if len(connect_parts) > 2 else DEFAULT_BROWSER_CDP_URL
-            _browser_connect(self, url)
-        elif sub == "disconnect":
-            _browser_disconnect(self)
-        elif sub == "status":
-            _browser_status()
-        else:
+        # The subcommand word is matched case-insensitively; the raw argument keeps
+        # its case because a CDP URL's path segment is case-sensitive.
+        parts = _command_arg(cmd).split(None, 1)
+        word = parts[0].lower() if parts else "status"
+        rest = parts[1].strip() if len(parts) > 1 else ""
+        handler = _BROWSER_SUBCOMMANDS.get(word)
+        if handler is None:
             _say_block(
                 "Usage: /browser connect|disconnect|status|use", "",
                 "   connect      Connect browser tools to your live Chromium-family browser session",
                 "   disconnect   Revert to default browser backend",
                 "   status       Show current browser mode",
                 "   use [off]    Switch to Browser Use mode (CLI 3.0) / back to built-in tools")
+            return
+        handler(self, rest.strip())
 
     # ---- /heartbeat, /refine, /review -----------------------------------------------------
     def _session_manager(self, getter, label: str):

tests/tools/test_browser_use_cli.py

@@ -814,6 +814,40 @@ class TestBrowserUseSlashCommand:
         assert stub.session_resets == 0
 
 
+class TestBrowserSlashDispatch:
+    """/browser routes through the _BROWSER_SUBCOMMANDS table: the subcommand word is
+    case-insensitive, the argument keeps its case (CDP URL paths are case-sensitive),
+    and an unknown word prints the usage block without touching any handler."""
+
+    def _run(self, cmd, monkeypatch):
+        import contextlib
+        import io
+
+        import hermes_cli.cli_commands_mixin as mod
+
+        calls = []
+        monkeypatch.setattr(mod, "_browser_connect", lambda cli, url: calls.append(("connect", url)))
+        monkeypatch.setattr(mod, "_browser_disconnect", lambda cli: calls.append(("disconnect",)))
+        monkeypatch.setattr(mod, "_browser_status", lambda: calls.append(("status",)))
+        buf = io.StringIO()
+        with contextlib.redirect_stdout(buf):
+            mod.CLICommandsMixin._handle_browser_command(object(), cmd)
+        return calls, buf.getvalue()
+
+    def test_connect_keeps_url_case_and_defaults_to_status(self, monkeypatch):
+        from hermes_cli.browser_connect import DEFAULT_BROWSER_CDP_URL
+
+        assert self._run("/browser CONNECT ws://127.0.0.1:9222/devtools/browser/AbC", monkeypatch)[0] == [
+            ("connect", "ws://127.0.0.1:9222/devtools/browser/AbC")]
+        assert self._run("/browser connect", monkeypatch)[0] == [("connect", DEFAULT_BROWSER_CDP_URL)]
+        assert self._run("/browser", monkeypatch)[0] == [("status",)]
+
+    def test_unknown_subcommand_prints_usage_only(self, monkeypatch):
+        calls, out = self._run("/browser frobnicate", monkeypatch)
+        assert calls == []
+        assert "Usage: /browser connect|disconnect|status|use" in out
+
+
 class TestNativeScreenshots:
     """Screenshots printed by capture_screenshot() attach directly to the
     model's context when it has native vision — no aux vision-LLM detour."""