feat(app): add selection add-to-chat flow with quick edit

[wufei-png]

Issue for this PR

Closes #14679

Type of change

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

What does this PR do?

This PR adds explicit file-selection actions in the session file view so selecting lines no longer forces the comment flow.

Changes included:

• adds a selection action bar with Add to chat and Quick edit
• inserts selected file ranges at the current prompt cursor position for message-scoped context
• adds quick-edit handoff into a new session
• localizes the new selection/quick-edit labels across supported app locales

This works by wiring selection action handlers in the file tab UI to prompt insertion + handoff state, and consuming handoff when opening a new session composer.

How did you verify your code works?

• manually selected lines in file view and confirmed action bar appears
• verified Add to chat inserts @file:start-end attachment at current cursor position
• verified Quick edit opens a new session with selected file context + instruction prefilled
• verified keybinds: mod+l (add to chat), mod+k (quick edit)

Screenshots / recordings

UI change. I can attach screenshots/recording if needed.

Checklist

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

Made with Cursor

[wufei-png]

here is an example:

2026-02-24.00-57-45.mov

it can have this effect:
explain this code@script/duplicate-pr.ts:7-13 and compare it with @script/duplicate-pr.ts:22-31

and the current is:

I don't think this is the best practice.

[github-actions]

Closing this pull request because it has had no updates for more than 60 days. If you plan to continue working on it, feel free to reopen or open a new PR.