fix: prevent comment continuation when '//' appears inside strings

[yogeshwaran-c]

What kind of change does this PR introduce?

Bug fix

What is the current behavior?

When pressing Enter on a line containing // inside a string literal (e.g. '//this is a string' or "http://localhost"), VS Code incorrectly treats it as a line comment and adds // on the next line.

For example:

let string = '//this is a string'.charAt(0)
// Pressing Enter after '.charAt(0)' produces:
let string = '//this is a string'.charAt(0)
// <-- unwanted comment continuation

Similarly with URLs:

axios.get("http://localhost/index").then()
// Pressing Enter produces:
axios.get("http://localhost/index").then()
// <-- unwanted comment continuation

Closes #241802

What is the new behavior?

Comment markers (//, /*, */) are now stripped from string and regex tokens during indentation context processing, just like brackets already are. This prevents the onEnter comment continuation rule from matching // that appears inside string literals, while preserving correct comment continuation behavior for actual line comments.

Additional context

Root cause: The IndentationLineProcessor.getProcessedTokens method already removes brackets from string/regex/comment tokens to prevent bracket-based indentation rules from being triggered by brackets inside strings. However, it did not remove comment markers from string/regex tokens, so the regex-based onEnter comment continuation rule could match // that appeared inside string content.

Fix approach: Added comment marker stripping (line comment token, block comment start/end tokens from the language configuration) for string and regex tokens, alongside the existing bracket stripping. This is a minimal, targeted fix that follows the same architectural pattern already used for brackets.

Files changed:

• src/vs/editor/common/languages/supports/indentationLineProcessor.ts — Strip comment markers from string/regex tokens
• src/vs/editor/contrib/indentation/test/browser/indentationLineProcessor.test.ts — Added tests for the fix