feat: integrate SearXNG web search service with platform capabilities

- Added SearXNG service configuration to Docker setup, including environment variables and health checks.
- Introduced new settings management for web search in the frontend, allowing users to enable/disable and configure search engines and language preferences.
- Updated backend to support web search functionality, including database schema changes and service integration.
- Implemented health check endpoint for the web search service and integrated it into the application.
- Removed legacy SearXNG API connector references in favor of the new platform service approach.

surfsense_web/messages/en.json

@@ -757,7 +757,27 @@
 		"general_reset": "Reset Changes",
 		"general_save": "Save Changes",
 		"general_saving": "Saving",
-		"general_unsaved_changes": "You have unsaved changes. Click \"Save Changes\" to apply them."
+		"general_unsaved_changes": "You have unsaved changes. Click \"Save Changes\" to apply them.",
+		"nav_web_search": "Web Search",
+		"nav_web_search_desc": "Built-in web search settings",
+		"web_search_title": "Web Search",
+		"web_search_description": "Web search is powered by a built-in SearXNG instance. All queries are proxied through your server — no data is sent to third parties.",
+		"web_search_enabled_label": "Enable Web Search",
+		"web_search_enabled_description": "When enabled, the AI agent can search the web for real-time information like news, prices, and current events.",
+		"web_search_status_healthy": "Web search service is healthy",
+		"web_search_status_unhealthy": "Web search service is unavailable",
+		"web_search_status_not_configured": "Web search service is not configured",
+		"web_search_engines_label": "Search Engines",
+		"web_search_engines_placeholder": "google,brave,duckduckgo",
+		"web_search_engines_description": "Comma-separated list of SearXNG engines to use. Leave empty for defaults.",
+		"web_search_language_label": "Preferred Language",
+		"web_search_language_placeholder": "en",
+		"web_search_language_description": "IETF language tag (e.g. en, en-US). Leave empty for auto-detect.",
+		"web_search_safesearch_label": "SafeSearch Level",
+		"web_search_safesearch_description": "0 = off, 1 = moderate, 2 = strict",
+		"web_search_save": "Save Web Search Settings",
+		"web_search_saving": "Saving...",
+		"web_search_saved": "Web search settings saved"
 	},
 	"homepage": {
 		"hero_title_part1": "The AI Workspace",