fix: preserve PowerShell argument arrays

[nightcityblade]

Fixes #1024

Summary

• splat PowerShell argument arrays when launching debugpy
• preserve each debug target argument as a separate process argument on Windows and Unix-like platforms

Validation

• npm run pretest
• full extension unit suite: 588 passing, 27 pending
• PowerShell parser validation
• end-to-end launcher check confirmed arg1 and arg2 remain separate

[Rich Chiodo (rchiodo)]

🔒 Automated review in progress — Rich Chiodo (@rchiodo) is auto-reviewing this PR.

[Rich Chiodo (rchiodo)]

Verification: The relevant tests could not be fully run in the isolated environment; this review is not fully verified.

Result: could-not-verify

Summary: Verification could not run because no trusted sandbox image is configured and local execution was not authorized. Static inspection confirmed the PowerShell `$args` splatting change and found no direct launcher argument-preservation test. Confidence is limited without executable validation.

Test runs: 1 not run

• ⚠️ Not run | Repository test discovery | git status --short && git branch --show-current && git diff --name-status upstream/main...HEAD && git diff --unified=40 upstream/main...HEAD -- bundled/scripts/noConfigScripts/debugpy.ps1 && node -e "const p=require('./package.json'); console.log(JSON.stringify(p.scripts,null,2))" && rg -n --glob "test" --glob ".ts" --glob ".ps1" "debugpy.ps1|noConfigScripts|BUNDLED_DEBUGPY_PATH|wait-for-client" .

⚠️ Repository test discovery diagnostic output

Container verification could not start: no trusted sandbox image is configured for microsoft/vscode-python-debugger, and local execution was not authorized.

[Rich Chiodo (rchiodo)]

Approved via Review Center.

[nightcityblade]

The code, test, lint, and CodeQL checks are green. The remaining Ensure Required Labels check requires exactly one of bug, debt, feature-request, or no-changelog; this PR fixes the argument-handling bug in #1024, but I do not have permission to apply the bug label. Could a maintainer add it when convenient?