Table editing, public page speed, and restore accuracy

This round focused on editing and saving notes that contain tables.

• Pasting a table — tables copied from elsewhere now keep their grid
• A vertical bar (|) inside a cell no longer shifts or drops the cell next to it
• Notes opened from a public link load much faster — the longer the note, the bigger the difference
• Restoring a backup is more accurate — if you attached the same file more than once, every copy comes back
• Search now works from a single character, including full-width characters
• Fixed a brief mismatch that could appear while switching languages
• When a sync problem keeps coming back, we no longer repeat the same notice — we tell you what to do next
• Cells that contain both a backslash and a vertical bar now save safely
• Tables stay intact even when a note mixes code blocks and tables
• Pasting a table as plain text now keeps every cell's content
• Restoring a large backup is further hardened so no rows go missing
• Fixed the language picker occasionally snapping back and freezing
• Error diagnostics are now better protected from including your note content