Replace numerous hardcoded English strings with I18n lookups (t / I18n.t) across controllers, views, helpers, and components, and convert model validation error messages to symbol keys. Added multiple locale files under config/locales for models and views. This centralizes user-facing notices/alerts, UI text, import/validation messages, and prepares the app for localization and easier translation maintenance.
* Allow CSV imports to be configured to a single account or multiple accounts
* Initialize import directly from accounts page
* Fix brakeman warnings
* Fix schema
* Fix Synth check
* Remove stale 1.0 import logic and model
* Fresh start
* Checkpoint before removing nav
* First working prototype
* Add trade, account, and mint import flows
* Basic working version with tests
* System tests for each import type
* Clean up mappings flow
* Clean up PR, refactor stale code, tests
* Add back row validations
* Row validations
* Fix import job test
* Fix import navigation
* Fix mint import configuration form
* Currency preset for new accounts
