VSC: Editor context bridge

[Hmbown]

Summary

Active editor selection plus file path are auto-included in turn context; @-mention autocomplete pulls from open files plus workspace.

Acceptance criteria

• Selecting code and invoking command sends both.
• @ works in composer.

Files

extensions/vscode/src/context.ts

Size

S

Source

Source tag: VSC. Add exact upstream/opencode source links during implementation if they are not already known. Do not copy external code blindly; port the behavior into this repo's architecture.

Filed from 2026-05-02 v0.8.8 intake.