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.

category-blacklist.csv

@@ -0,0 +1,4 @@
+id,name
+229534,Software
+283155,Books
+16310101,Grocery Gourmet Food