## What changed
This PR moves the shared VS Code development workflow to the repository
root.
It adds repo-level `.vscode/launch.json` and `.vscode/tasks.json` so
contributors can debug `clice` and the VS Code extension from the root
workspace with relative paths.
The checked-in tasks are intentionally limited to extension-side `pnpm`
workflows such as installing dependencies and running the extension
watcher. They do not build the `clice` executable or unit tests.
It also updates `.gitignore` to allow only those two shared VS Code
config files to be committed, while continuing to ignore other local
`.vscode` files.
Finally, it removes the duplicate `editors/vscode/.vscode` folder so
there is a single supported VS Code setup in the repo.
## Why
The previous setup split VS Code configs between local-only root files
and tracked configs under `editors/vscode/.vscode`, which made the
development/debug flow less consistent.
Keeping only extension-side tasks avoids baking a specific native build
workflow into committed editor config while still making extension
development usable out of the box.
## Developer impact
Contributors can now open the repository root in VS Code and use the
checked-in launch/tasks configs directly.
The extension debug configs only disable competing C/C++ language
extensions (`clangd` and `cpptools`) instead of disabling every
extension.
All committed paths remain relative to `${workspaceFolder}`.
## Validation
- Ran `python3 -m json.tool .vscode/launch.json`
- Ran `python3 -m json.tool .vscode/tasks.json`
