[Feature]: Option to disable Chrome tab group creation ("OpenCLI Browser" orange group)

Feature Request

Problem

Every time OpenCLI opens a browser tab via opencli browser <session> open ..., the Chrome extension creates (or reuses) a tab group named "OpenCLI Browser" with orange color. Over time, empty/abandoned groups accumulate in Chrome, cluttering the tab bar:

• Restarting Chrome → old window gone, new window + new group created next time
• Using different session names → potentially multiple groups
• No way to prevent this behavior

This is especially disruptive for users who already have structured tab management (e.g., custom manual groups, Tab Groups for projects) — the auto-created "OpenCLI Browser" group feels invasive.

Root Cause

In the Chrome extension's background.js:

const CONTAINER_TAB_GROUP_TITLE = {
  interactive: "OpenCLI Browser",
  automation: "OpenCLI Adapter",
};
const OWNED_TAB_GROUP_COLOR = "orange";

The ensureOwnedContainerGroup() → createOwnedGroup() path always creates/ensures a tab group. There is no configuration to opt out.

Requested Solution

Add a configuration option to disable automatic tab group creation, ideally in one of these forms:

1. Environment variable — e.g. OPENCLI_NO_TAB_GROUP=1 (simplest, easy to set in .zshrc)
2. CLI flag — e.g. opencli --no-group browser <session> open ... or through the --profile mechanism
3. Extension preference — a toggle stored via chrome.storage.local that the CLI can set once

Behavior When Disabled

When the option is active:

• The extension still manages its own owned Chrome window
• Tabs are opened in that window normally, but not grouped into a named/colored tab group
• All other functionality (session management, tab lease, idle timeout) remains unchanged

Workaround

Users can currently use opencli browser <session> bind to bind to an existing tab (avoids creating new windows/groups), but this is not suitable for all workflows (e.g. automation, multi-session browsing).

Environment

• OpenCLI: (check with opencli --version)
• Extension: 1.0.21
• Chrome: latest