feat(browser): /browser connect — attach browser tools to live Chrome via CDP

Add /browser slash command for connecting browser tools to the user's
live Chrome instance via Chrome DevTools Protocol:

  /browser connect       — connect to Chrome on localhost:9222
  /browser connect ws://host:port  — custom CDP endpoint
  /browser disconnect    — revert to default (headless/Browserbase)
  /browser status        — show current browser mode + connectivity

When connected:
- All browser tools (navigate, snapshot, click, etc.) control the
  user's real Chrome — logged-in sessions, cookies, open tabs
- Platform-specific Chrome launch instructions are shown
- Port connectivity is tested immediately
- A context message is injected so the model knows it's controlling
  a live browser and should be mindful of user's open tabs

Implementation:
- BROWSER_CDP_URL env var drives the backend selection in browser_tool.py
- New _create_cdp_session() creates sessions using the CDP override
- _get_cdp_override() checked before local/Browserbase selection
- Existing agent-browser --cdp flag handles the actual CDP connection

Inspired by OpenClaw's browser profile system.

hermes_cli/commands.py

@@ -45,6 +45,7 @@ COMMANDS_BY_CATEGORY = {
         "/skills": "Search, install, inspect, or manage skills from online registries",
         "/cron": "Manage scheduled tasks (list, add/create, edit, pause, resume, run, remove)",
         "/reload-mcp": "Reload MCP servers from config.yaml",
+        "/browser": "Connect browser tools to your live Chrome (usage: /browser connect|disconnect|status)",
     },
     "Info": {
         "/help": "Show this help message",