Adding inlineDiffs for unified-cell diffs

[nakul-py]

Description

This PR adds inlineDiffs for unified-cell diffs as a new command argument as allowInlineDiffs
By default it is false for current.

Screencast.From.2025-10-30.11-45-47.mp4

• Closes Expose a new command argument for allowInlineDiffs #27
• CC @jtpio @Zsailer

Additional code to test inlineDiffs in details.

void window.jupyterapp.commands.execute('jupyterlab-diff:unified-cell-diff', {
  originalSource: `def add():
    x = 10
    y = 20
    total = x + y
    print("Sum is:", total)
    message = "Result computed successfully"
    print("Message:", message)
    return total`,

  newSource: `def add(a, b):
    x = a
    y = b + 1
    total = x + y
    print("Sum is now:", total)
    msg = "Computation done successfully!"
    print("Info:", msg)
    return total`,

  showActionButtons: true,
  allowInlineDiffs: true
});

[jtpio]

Let's document that new argument in the README.md?

Also maybe we could also add it to the unified-file-diff command? (for file diffs)

[nakul-py]

Let's document that new argument in the README.md?

Yes we can :)

Also maybe we could also add it to the unified-file-diff command? (for file diffs)

Yes i also implemented it for unified-file-diff but cannot able to test it as the error comes No editor found for file so i removed the changes for unified-file-diff.

[nakul-py]

I think unified-file-diff not supports notebook because it worked in .py file but not worked in .ipynb file.

[nakul-py]

@jtpio will we can also add inlineDiffs for spilt-cell also?

[jtpio]

Maybe we don't need to include that argument in these small examples, especially if the default is false (same for the other example below).

[nakul-py]

Done

[jtpio]

Thanks!