feat: transition bestseller analysis storage to SQLite and add category blacklist

- Replaces Excel output with structured database tables for tracking category analysis runs and product results.
- Implements a blacklist to exclude specific category IDs from the bestseller pipeline.
- Adds unit tests for category processing and enhances logging with levels and timestamps.
- Introduces foreign key enforcement and updated schema definitions in the database module.

.gitignore

@@ -33,11 +33,13 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 # Finder (MacOS) folder config
 .DS_Store
 *.xlsx
-*.csv
-
 
 results.db
 
 results.db-shm
 
 results.db-wal
+
+output/
+
+temp_output/