Plan:
1.  **Fix Syntax Error:** I identified that the JavaScript code for age calculation in `includes/layout/footer.php` contained Python-style comments (`#`), causing a syntax error.
2.  **Correct Comments:** I created and executed a Python script (`fix_footer_js.py` and `fix_footer_js_v2.py`) to replace these with valid JavaScript comments (`//`).
3.  **Verify:** I verified the file content to ensure the syntax is now correct.

Changed:
*   `includes/layout/footer.php`: Replaced invalid `#` comments with `//` in the JavaScript section at the end of the file.

Notes:
*   The automatic age-to-DOB calculation (and vice-versa) should now work correctly when you type in the "Age" field.
*   The script listens for input on the Age field and sets the DOB to `YYYY-01-01`.

Next: Please try entering the age again in the "Add Patient" or "Edit Patient" modal. It should now automatically populate the Date of Birth field.
Reminder: Click Save in the editor to sync changes.