Error tests, FK violations fix

- ErrorHandler tests: 77 assertions covering FK extraction, normalization, dedup, edge cases. Fix FK table map for child tables.
- Fix FK violation: (int)null → 0 in createThesis for orientation/ap/finality/license FK columns. Add FK value logging to updateThesis.
- Add CURRENT_ISSUES.md with summary of FK violation, dev debugging, and tag dedup status for next conversation

app/public/admin/add.php

@@ -39,7 +39,9 @@ function withAutofocus(string $fieldName, array $attrs = []): array {
 
 function old($key, $default = "") {
     global $formData;
-    return isset($formData[$key]) ? htmlspecialchars($formData[$key]) : $default;
+    if (!isset($formData[$key])) return $default;
+    if (is_array($formData[$key])) return $formData[$key]; // Return raw array for callers that handle it
+    return htmlspecialchars($formData[$key]);
 }
 
 function wasSelected($key, $value) {