Title: Two browser provider bugs: Camofox missing from registry + reconfigure flow leaks use_gateway

Body:

Found two bugs while switching browser providers via hermes setup tools.

Bug 1: Camofox missing from _PROVIDER_REGISTRY

File: tools/browser_tool.py (~line 388)

_PROVIDER_REGISTRY: Dict[str, type] = {
    "browserbase": BrowserbaseProvider,
    "browser-use": BrowserUseProvider,
    "firecrawl": FirecrawlProvider,
}

"camofox" is not registered. Setting browser.cloud_provider: camofox in config.yaml has no effect on standard browser tools (browser_navigate, etc.) — they fall back to Browser Use or Browserbase instead. Camofox only works through the separate camofox_* functions.

Expected: camofox should be a valid registered provider so cloud_provider: camofox routes standard browser tools through Camofox.

Bug 2: _reconfigure_provider never updates browser.use_gateway

File: hermes_cli/tools_config.py, _reconfigure_provider (~line 1535)

When using "Reconfigure an existing tool's provider or API key" to switch browser providers, the function updates browser.cloud_provider but does not update browser.use_gateway.

The new-tool flow (_configure_provider, ~line 1299) correctly does:

browser_cfg["use_gateway"] = bool(managed_feature)

But _reconfigure_provider omits this entirely. If a user switches from a Nous-managed provider (where use_gateway: true) to a self-hosted provider, the stale use_gateway: true remains in config and can cause routing issues.

Expected: _reconfigure_provider should set browser_cfg["use_gateway"] = bool(managed_feature) to match _configure_provider.

Environment: Hermes Agent CLI, macOS, Python 3.11