feat: add knowledge module caching layer (closes #79)

.env.example

@@ -37,6 +37,12 @@ VALKEY_URL=redis://localhost:6379
 VALKEY_PORT=6379
 VALKEY_MAXMEMORY=256mb
 
+# Knowledge Module Cache Configuration
+# Set KNOWLEDGE_CACHE_ENABLED=false to disable caching (useful for development)
+KNOWLEDGE_CACHE_ENABLED=true
+# Cache TTL in seconds (default: 300 = 5 minutes)
+KNOWLEDGE_CACHE_TTL=300
+
 # ======================
 # Authentication (Authentik OIDC)
 # ======================