Add "Publish now" button to note editor to publish a single note

[jspada200]

Summary

Add a "Publish now" button in the note editor footer (next to text controls) so users can publish only the current note, with a confirmation dialog before publishing.

Details

Today users can only publish all notes. We want to support publishing a single note from the note editor.

• Placement: In the footer of the note editor, next to the existing text controls (e.g. formatting/bold/italic).
• Control: A small button labeled "Publish now".
• Flow: On click, show a confirm dialog (e.g. "Publish this note?"). If the user confirms, publish only that note; if they cancel, do nothing.
• Scope: UI and flow only; backend may already support single-note publish or may need an endpoint. Implementation should use existing publish behavior where it applies to one note.

Likely area: note editor component and its footer (and any shared publish API/provider).

Acceptance criteria

• "Publish now" button is visible in the note editor footer next to the text controls.
• Clicking "Publish now" opens a confirmation dialog (e.g. "Publish this note?" with confirm/cancel).
• Confirming publishes only the current note (not all notes).
• Canceling closes the dialog and does not publish.
• All changes tested locally
• All relevant automated tests complete successfully
• Verified no existing workflows broken
• For UI changes, screenshots or gif animations of the changes included
• Steps to test included in PR