Add SearXNG web search for current information

- Add searxng.py service for web queries via SearXNG API
- Integrate search into ai_chat.py with AI-driven search decisions
- AI determines if query needs current info, then searches automatically
- Add SEARXNG_URL, SEARXNG_ENABLED, SEARXNG_MAX_RESULTS config options
- Update documentation in README.md, CLAUDE.md, and .env.example

.env.example

@@ -49,6 +49,18 @@ BOT_STATUS=for mentions
 # Number of messages to remember per user (higher = more context, more tokens)
 MAX_CONVERSATION_HISTORY=20
 
+# ===========================================
+# Web Search (SearXNG)
+# ===========================================
+# SearXNG instance URL for web search (enables the bot to access current information)
+SEARXNG_URL=https://search.example.com
+
+# Enable/disable web search capability (true/false)
+SEARXNG_ENABLED=true
+
+# Maximum number of search results to fetch (1-20)
+SEARXNG_MAX_RESULTS=5
+
 # ===========================================
 # Logging
 # ===========================================