feat(tools): add support for self-hosted firecrawl

Adds optional FIRECRAWL_API_URL environment variable to support
self-hosted Firecrawl deployments alongside the cloud service.

- Add FIRECRAWL_API_URL to optional env vars in hermes_cli/config.py
- Update _get_firecrawl_client() in tools/web_tools.py to accept custom API URL
- Add tests for client initialization with/without URL
- Document new env var in installation and config guides

tests/tools/test_web_tools_config.py

@@ -0,0 +1,49 @@
+"""Tests for Firecrawl client configuration."""
+
+import os
+import pytest
+from unittest.mock import patch, MagicMock
+
+
+class TestFirecrawlClientConfig:
+    """Test suite for Firecrawl client initialization with API URL support."""
+
+    def teardown_method(self):
+        """Reset client between tests."""
+        import tools.web_tools
+
+        tools.web_tools._firecrawl_client = None
+
+    def test_client_with_api_key_only(self):
+        """Test client initialization with only API key (no custom URL)."""
+        env_vars = {"FIRECRAWL_API_KEY": "test-key"}
+        env_vars.pop("FIRECRAWL_API_URL", None)
+
+        with patch.dict(os.environ, env_vars, clear=False):
+            # Remove FIRECRAWL_API_URL from env if it exists
+            if "FIRECRAWL_API_URL" in os.environ:
+                del os.environ["FIRECRAWL_API_URL"]
+
+            with patch("tools.web_tools.Firecrawl") as mock_firecrawl:
+                from tools.web_tools import _get_firecrawl_client
+
+                _get_firecrawl_client()
+                mock_firecrawl.assert_called_once_with(api_key="test-key")
+
+    def test_client_with_api_key_and_url(self):
+        """Test client initialization with API key and custom URL."""
+        with patch.dict(
+            os.environ,
+            {
+                "FIRECRAWL_API_KEY": "test-key",
+                "FIRECRAWL_API_URL": "http://localhost:3002",
+            },
+            clear=False,
+        ):
+            with patch("tools.web_tools.Firecrawl") as mock_firecrawl:
+                from tools.web_tools import _get_firecrawl_client
+
+                _get_firecrawl_client()
+                mock_firecrawl.assert_called_once_with(
+                    api_key="test-key", api_url="http://localhost:3002"
+                )