fix: always prepend separator when appending noConfigScripts to PATH (#1637)

[wenytang-ms]

Fixes #1637

Problem

vscode.EnvironmentVariableCollection.append('PATH', value) does literal string concatenation — it does not insert a path separator. The current code in src/noConfigDebugInit.ts tries to compensate by checking process.env.PATH:

const currentPath = process.env.PATH || '';
const needsSeparator = currentPath.length > 0 && !currentPath.endsWith(pathSeparator);
const pathValueToAppend = needsSeparator ? `` : noConfigScriptsDir;
collection.append('PATH', pathValueToAppend);

But process.env.PATH is the extension host's PATH, which is not necessarily the PATH used by the integrated terminal (it can be modified by terminal.integrated.env. or by other extensions' env-var collections). When the extension host PATH ends with ; but the resolved terminal PATH does not, needsSeparator is same, and the directory gets appended with no separator — collapsing it into the last entry of the user's PATH.

That is exactly what the user reports in #1637:

...;C:\Program Files\jreleaser\c:\Users\REDACTED\.vscode\extensions\vscjava.vscode-java-debug-0.59.0\bundled\scripts\noConfigScripts

Fix

Always prepend the separator. If the user's PATH already ends with one, the resulting double separator just creates an empty entry, which both Windows and POSIX shells handle safely.

Verification

• npx tsc -p . --noEmit ✅
• npm run tslint ✅