* Reorganizing code into more logical modules:
- `routes` specifically for Rocket handler functions
- `receipts` data model for receipts
- `transactions` for Firefly transactions
* Encapsulate database operations for receipts using the repository
pattern; move SQL queries to external files (`sqlx` can only use
string literals or external files for queries, not variables or
constants)
* Remove obsolete routes, templates for old transaction-focused pages
Dustin