Expose relation fields in the champ pickers and fix their column resolution

data_definition_options() used to exclude relation-type fields from its field list entirely, so a filter/binding could never reference "the linked object" of a row — and even when a relation field's clean name was typed manually (as the earlier "level.parcour" example needed), it silently matched nothing: every column lookup for a filter/repeater field used the field's own name, but a relation is actually stored in a "<field>_id" column (see create_definition.py), so the lookup always missed.

Relation fields now appear in the champ dropdowns (Répéteur's filtre_champ/filtre2_champ, Donnée liée's data_filtre_champ/data_filtre2_champ) labeled with the object they point to (e.g. "parcour (→ parcours)"), and a new _field_column() helper in filter_repeater_rows.py resolves the right "<field>_id" column whenever the field turns out to be a relation — used consistently by the filter comparison itself, the "{{Objet.champ}}" dynamic-value resolver, the repeater's row content ({{champ}}), and the Donnée liée row context. Jauge's own champ/champ_nom pickers (which need an actual displayable value, not an id) still exclude relations, both server- and client-side.

Verified end to end: the dropdown shows the relation field with its target-object label, and filtering "level" rows by the clean relation field name "parcour" (not "parcour_id") against a dynamic {{game.current_parcours}} reference now actually matches, alongside the existing "number" filter. Full suite green (89).

screens/rendering/render_repeater.py

@@ -5,7 +5,7 @@ import db
 from .style_string import _style_string
 from .auto_id import _auto_id
 from .apply_ctx import _apply_ctx
-from .filter_repeater_rows import filter_repeater_rows
+from .filter_repeater_rows import filter_repeater_rows, _field_column
 from ..element_types.load_template_tree import _load_template_tree
 
 
@@ -32,7 +32,7 @@ def _render_repeater(el, meta, slug, children_map, ctx=None, parent_flex_directi
     # qu'on sait que l'objet est valide.)
     rows = db.list_rows(slug, definition)
     rows = filter_repeater_rows(slug, definition, rows, attrs_raw)
-    field_cols = {f["name"]: db.slugify(f["name"]).replace("-", "_") for f in definition["fields"]}
+    field_cols = {f["name"]: _field_column(definition, f["name"]) for f in definition["fields"]}
 
     # Modèle de ligne = un élément de jeu (conteneur stylisé réutilisable) :
     # on recharge son arbre EN DIRECT à chaque ligne de données (jamais copié