App: link opening, all-day deadlines, and attachment integrity

The Android app's link, calendar, and file layers now match the web's standards.

• Email (mailto) and phone (tel) links in notes now open in the app — unsafe address formats stay blocked, same as the web
• Fixed all-day event deadlines that could disappear under certain timezone settings
• Hardened the attachment share-state calculation so file integrity is more robust
• Fixed partially-failed upload notices that showed only an oversized title