#7764: Rename escape function for double quotes

This name forces the reader (or the next LLM) to understand the mechanism, not just the outcome. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR is a small internal refactor in `src/infra/exec-approvals.ts` that renames the double-quote escape helper and its backing constant to better describe the mechanism (characters that are escapable after a backslash inside a double-quoted context). All in-file call sites were updated, and there are no external references since the helper/constant are not exported. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk. - The change is limited to renaming a private constant and helper function within a single file, and all in-file call sites are updated; repo-wide search shows no remaining references to the old identifiers. - No files require special attention <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->