feat(browser): multi-provider cloud browser support + Browser Use integration

Introduce a cloud browser provider abstraction so users can switch
between Local Browser, Browserbase, and Browser Use (or future providers)
via hermes tools / hermes setup.

Cloud browser providers are behind an ABC (tools/browser_providers/base.py)
so adding a new provider is a single-file addition with no changes to
browser_tool.py internals.

Changes:
- tools/browser_providers/ package with ABC, Browserbase extraction,
  and Browser Use provider
- browser_tool.py refactored to use _PROVIDER_REGISTRY + _get_cloud_provider()
  (cached) instead of hardcoded _is_local_mode() / _create_browserbase_session()
- tools_config.py: generic _is_provider_active() / _detect_active_provider_index()
  replace TTS-only logic; Browser Use added as third browser option
- config.py: BROWSER_USE_API_KEY added to OPTIONAL_ENV_VARS + show_config + allowlist
- subprocess pipe hang fix: agent-browser daemon inherits pipe fds,
  communicate() blocks. Replaced with Popen + temp files.

Original PR: #1208
Co-authored-by: ShawnPana <shawnpana@users.noreply.github.com>

hermes_cli/config.py

@@ -507,6 +507,14 @@ OPTIONAL_ENV_VARS = {
         "password": False,
         "category": "tool",
     },
+    "BROWSER_USE_API_KEY": {
+        "description": "Browser Use API key for cloud browser (optional — local browser works without this)",
+        "prompt": "Browser Use API key",
+        "url": "https://browser-use.com/",
+        "tools": ["browser_navigate", "browser_click"],
+        "password": True,
+        "category": "tool",
+    },
     "FAL_KEY": {
         "description": "FAL API key for image generation",
         "prompt": "FAL API key",
@@ -1258,6 +1266,7 @@ def show_config():
         ("VOICE_TOOLS_OPENAI_KEY", "OpenAI (STT/TTS)"),
         ("FIRECRAWL_API_KEY", "Firecrawl"),
         ("BROWSERBASE_API_KEY", "Browserbase"),
+        ("BROWSER_USE_API_KEY", "Browser Use"),
         ("FAL_KEY", "FAL"),
     ]
     
@@ -1404,7 +1413,7 @@ def set_config_value(key: str, value: str):
     # Check if it's an API key (goes to .env)
     api_keys = [
         'OPENROUTER_API_KEY', 'OPENAI_API_KEY', 'ANTHROPIC_API_KEY', 'VOICE_TOOLS_OPENAI_KEY',
-        'FIRECRAWL_API_KEY', 'FIRECRAWL_API_URL', 'BROWSERBASE_API_KEY', 'BROWSERBASE_PROJECT_ID',
+        'FIRECRAWL_API_KEY', 'FIRECRAWL_API_URL', 'BROWSERBASE_API_KEY', 'BROWSERBASE_PROJECT_ID', 'BROWSER_USE_API_KEY',
         'FAL_KEY', 'TELEGRAM_BOT_TOKEN', 'DISCORD_BOT_TOKEN',
         'TERMINAL_SSH_HOST', 'TERMINAL_SSH_USER', 'TERMINAL_SSH_KEY',
         'SUDO_PASSWORD', 'SLACK_BOT_TOKEN', 'SLACK_APP_TOKEN',