This PR addresses two issues in the backlink generation logic within src/lib/content/backlinks.ts:

1. Incorrect Path for README Files: Backlinks pointing to files named README.md (or similar variations like readme.md) were incorrectly including /readme in the final path (e.g., /careers/hiring/readme). This change ensures that such paths are correctly resolved to the parent directory (e.g., /careers/hiring).
2. Incorrect Title Display: The title for some backlinks was defaulting to the filename component (e.g., "readme") instead of using the actual title defined in the markdown frontmatter or the database. The logic has been updated to prioritize the title fetched from the vault.parquet database first, then fall back to the markdown frontmatter title, and only use the path component as a last resort.

These changes improve the accuracy and presentation of backlinks in the "MENTIONED IN" section.