Major refactor: security enhancements, modularization, config integration, reduced Parquet reliance

- Migrated codebase to class-based architecture for better modularity and maintainability
- Introduced system_config.json for centralized configuration (required for runtime)
- Added structured working directories for improved file organization
- Significantly reduced reliance on Parquet; replaced with alternative data handling
- Implemented security improvements across modules
- Several TODOs remain in the main script for future enhancements
- Linter formatting affected readability in some files (e.g., utils); cleanup is on the agenda

.gitignore

@@ -6,4 +6,7 @@
 chunkinator.json
 jobs.json
 *.xl*
-.exe
+.exe
+securitytest.py
+*.toml
+system_config.json