Optimize affiliate system and add locale-aware defaults

- Show BOM button for unsaved loads (no longer requires save first)
- Set US fallback affiliate tag for unknown countries
- Localize Amazon search queries in all 5 languages (EN/DE/ES/FR/NL)
- Add affiliate URL/country fields to SavedBattery model
- Auto-detect unit system (imperial for US locale, metric otherwise)
- Set charger input voltage based on locale (120V US, 230V EU)
- Remove StoreKitManager and CableProPaywallView
- Add CLAUDE.md project instructions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Cable/Base.lproj/Localizable.strings

@@ -83,6 +83,12 @@
 "bom.navigation.title" = "Bill of Materials";
 "bom.navigation.title.system" = "BOM – %@";
 "bom.size.unknown" = "Size TBD";
+"bom.search.battery" = "%dAh %dV %@ battery";
+"bom.search.cable.black" = "%@ black battery cable";
+"bom.search.cable.red" = "%@ red battery cable";
+"bom.search.device.fallback" = "DC device %.0fW %.0fV";
+"bom.search.fuse" = "inline fuse holder %dA";
+"bom.search.terminals" = "%@ cable shoes";
 "bom.terminals.detail" = "Ring or spade terminals sized for %@ wiring";
 "bom.empty.message" = "No components saved in this system yet.";
 "bom.export.pdf.button" = "Export PDF";