centralise repertoire filter column rendering

- shared repFilterEntry() and  config array
- shared repFilterEntry() and $filterColumns config array
- fix single-valued FK fading via full intersection

TODO.md

@@ -75,6 +75,18 @@
 - [x] `templates/admin/edit.php` — moved `.admin-form-footer` from bottom to top-right, right after `<h1>`
 - [x] `admin.css` — added `.admin-form-footer--sticky` variant with `position:sticky; top:0; justify-content:flex-end`
 
+## Fix CSV importer robustness
+- [x] Pad rows to expected column count to avoid offset warnings from short rows
+- [x] Distinguish `$yearRaw !== ''` before `intval()` to handle empty-year rows correctly
+- [x] Improve missing-field error message: lists which fields are missing, includes identifier/title snippet
+
+## Standardise répertoire filter column rendering
+- [x] Centralise filter column rendering into a shared `repFilterEntry()` function
+- [x] Define `$filterColumns` config array as single source of truth for the 5 filter columns
+- [x] All columns (years, ap, or, fi, kw) now share identical fade/select/HTMX logic via the same code path
+- [x] Fix single-valued FK columns (years, ap, or, fi): matched entries now use full intersection so clicking one entry correctly fades others with zero results
+- [x] Fix column ordering: students between finalité and mots-clés
+
 ## Standardise buttons with .btn base class
 - [x] Create `.btn` base class in common.css: `border-radius: 10px; padding: var(--space-xs)` + background + cursor
 - [x] Add `.btn--primary` (accent bg), `.btn--secondary` (--bg bg + border), `.btn--sm`, `.btn--lg`, `.btn--danger`, `.btn--warning`, `.btn--success`, `.btn--ghost`, `.btn--muted`, `.btn--blue`, `.btn--yellow`, `.btn--green`, `.btn--red` modifiers