refactor: improve database initialization and news fetching structure

backend/example.env

@@ -1,8 +1,29 @@
 # URL for the Ollama service
 OLLAMA_HOST=http://localhost:11434
 
-# Interval for scheduled news fetching in hours (minimum: 0.5)
+# Interval for scheduled news fetching in hours
 CRON_HOURS=1
 
+# Minimum interval for scheduled news fetching in hours
+MIN_CRON_HOURS=0.5
+
+# Cooldown period in minutes between manual syncs
+SYNC_COOLDOWN_MINUTES=30
+
+# LLM model to use for summarization
+LLM_MODEL=qwen2:7b-instruct-q4_K_M
+
+# Timeout in seconds for LLM requests
+LLM_TIMEOUT_SECONDS=180
+
+# Timeout in seconds for Ollama API requests
+OLLAMA_API_TIMEOUT_SECONDS=10
+
+# Timeout in seconds for article fetching
+ARTICLE_FETCH_TIMEOUT=30
+
+# Maximum length of article content to process
+MAX_ARTICLE_LENGTH=5000
+
 # SQLite database connection string
-DATABASE_URL=sqlite:///./newsdb.sqlite
+DB_NAME=owlynews.sqlite3