feat: add debug test support

[k1w1]

Summary

• Adds Debug test, Debug test file, and Debug latest test commands that launch the VS Code Node debugger (pwa-node) instead of running in a terminal
• Adds "Debug test" and "Debug tests for this file" CodeLenses alongside the existing run lenses
• Adds a Debug run profile to the VS Code Test Explorer (the triangular debug icon next to each test)
• New keyboard shortcuts: Ctrl+Alt+D (debug test at cursor), Ctrl+Alt+Shift+D (debug test file)

How it works

A new DebugInvoker class (src/debugger/index.ts) calls vscode.debug.startDebugging() with a pwa-node launch config that invokes npm run <script> -- --files <file> --tests <name>. This lets VS Code attach its debugger so breakpoints set inside test files are hit normally.

The approach mirrors what the vitest VS Code extension does — using vscode.debug.startDebugging with runtimeExecutable: 'npm' and autoAttachChildProcesses: true.

Test plan

• Open a Japa test file — "Run test" and "Debug test" CodeLenses appear above each test
• Click Debug test — VS Code debug session starts, breakpoints in the test file are hit
• Click Debug tests for this file — debugger runs all tests in the file
• Use Ctrl+Alt+D shortcut to debug the test at the cursor
• Use the Test Explorer debug profile (triangular play icon) to debug selected tests
• Confirm Run code paths are unaffected

[k1w1]

Woah, I got a bit ahead of myself here. I thought I was just pushing this up to my fork. I have some more validation to do.

[k1w1]

I have verified that it works as expected on my project. Debug buttons appear, and function, and debugging stops at breakpoints in the test and anywhere else in the code.

5/10 unit tests are failing, but that is the same as main.

Link above test to debug:

Button to debug next to each test:

Debugging related commands: