Bug: Bold formatting is inconsistent or fails in certain cases

[camiicode]

Problem:
The bold formatting feature does not behave consistently.

When selecting text and applying bold formatting via:

• CTRL + B, or
• Right click → contextual menu → Bold

the action sometimes works correctly, but in other cases:

• Nothing happens
• Only one level of bold is applied
• The bold state becomes inconsistent

The app supports two bold levels (semibold and extrabold),
triggered by applying the bold action consecutively.
However, in many cases the expected level is not applied.

This issue became especially noticeable when pasting text
and trying to apply bold formatting.

Expected behavior:

• Bold formatting should always apply to selected text.
• Consecutive bold actions should reliably cycle through:
  normal → semibold → extrabold → normal.
• Behavior should be consistent regardless of how the text
  was inserted (typed or pasted).

Possible causes:

• Selection range is lost after paste.
• Formatting logic does not correctly detect current font-weight.
• Event handling conflicts between keyboard shortcut
  and contextual menu actions.

Steps to reproduce:

1. Paste text into a note.
2. Select a portion of the text.
3. Press CTRL + B or use the contextual menu.
4. Repeat the action multiple times.
5. Observe inconsistent or missing bold formatting.

Acceptance criteria:

• Bold formatting always applies to selected text.
• Bold state cycles predictably.
• Works consistently with pasted and typed text.