fix(tui): handle ESC to return to provider list rather than closing modal

[ANSHSINGH050404]

Issue for this PR

Closes #14931

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

When adding a provider, pressing ESC inside the API key input or authorization code dialog previously closed the entire provider modal stack.

This happened because the root <Dialog /> layout (dialog.tsx) was trapping the Escape key globally and popping the stack by default.

To fix this:

1. I updated dialog.replace() to accept an optional onEscape handler. If the handler returns false, the root dialog skips its default closing behavior.
2. I passed a custom onBack handler to the ApiMethod, CodeMethod, and AutoMethod views that pushes <DialogProvider /> back onto the view stack and halts the default closing behavior.

How did you verify your code works?

I ran the TUI (bun dev), opened the "Connect a provider" menu, selected a provider, and hit ESC while in the API key / Auth Code prompt. I verified that it successfully returned me to the provider list without closing the modal.

Screenshots / recordings

Before

opencode-1.mp4

After

opencode-2.mp4

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[ANSHSINGH050404]

"Hi @palmamartin @vvarp @ndarilek — I've submitted this PR to fix the issue where the ESC key was closing the entire provider modal instead of navigating back.

[ndarilek]

I'm going to start adding people who randomly CC me on issues to a list I spam on every single comment I make on any repo's issues. Ready to start getting spam for Godot, jj, and a bunch of other repos you have no commit rights on? Buckle up!