Replace fragile price change detection in Purchase.save() with a
lazy dirty flag approach. A pre_save/post_save signal pair detects
price/currency changes without extra DB queries, and convert_prices()
uses the flag to determine which purchases need conversion.
- Add needs_price_update BooleanField with db_index
- Add pre_save signal to store old price/currency values
- Add post_save signal to set needs_price_update=True when price/currency changes
- Simplify Purchase.save() to remove DB reload + comparison logic
- Remove price_or_currency_differ_from() method
- Update convert_prices() to filter on needs_price_update flag
- Extract _get_exchange_rate() and _save_converted_price() helpers
- Add tests for the new behavior
* ignore English articles when sorting names
* added a new sort_name field that gets automatically created
* automatically fill certain values in forms:
* new game: name and sort name after typing
* new edition: name and sort name when selecting game
* new purchase: platform when selecting edition
* More fields are now optional. This is to make it easier to add new items in bulk.
* Game: Wikidata ID
* Edition: Platform, Year
* Purchase: Platform
* Platform: Group
* Session: Device
* New fields:
* Game: Year Released
* To record original year of release
* Upon migration, this will be set to a year of any of the game's edition that has it set
* Purchase: Date Finished
* Editions are now unique combination of name and platform
lukas
