Replaced hardcoded 'de-DE' locale with a new getCurrentCulture function that selects the user's culture from localized.culture or navigator.language. Date formatting now adapts to user language settings in detailedCurrentDate and getLocaleDateString.
- Updated `mapSignature` to filter signature annotations by `pageIndex` when finding nearest elements.
- Ensures correct association of frames and signature data for each page.
- Prevents errors caused by cross-page annotation references.
