fix: prevent URLSpan(null) crash on unedited link tap

[Arvuno]

Summary

Fixes a crash when tapping an unedited link (one that was inserted but never had its URL set via the edit dialog).

Problem

When a link is inserted from the toolbar without being edited, URLSpan(null) is created with a null URL. When tapped, the LinkMovementMethod callback in TakeNote.kt calls Uri.parse(link) where link is null, causing a crash.

Fix

In the 'Open Link' handler, check if span.URL is null before attempting to parse and open it. If null, display the 'Can't open link' toast instead of crashing.

Changes

• Modified TakeNote.kt to use span.URL directly and guard against null values

Testing

• Insert a link via toolbar without editing it (so URL is null)
• Tap the link and verify the app doesn't crash
• Should show 'Can't open link' toast instead