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/resolve_bound_row.py

@@ -1,6 +1,6 @@
 import db
 
-from .filter_repeater_rows import filter_repeater_rows
+from .filter_repeater_rows import filter_repeater_rows, _field_column
 
 
 def _resolve_bound_row_ctx(slug, attrs):
@@ -35,4 +35,4 @@ def _resolve_bound_row_ctx(slug, attrs):
     if not rows:
         return None
     row = rows[0]
-    return {f["name"]: str(row.get(db.slugify(f["name"]).replace("-", "_"), "") or "") for f in definition["fields"]}
+    return {f["name"]: str(row.get(_field_column(definition, f["name"]), "") or "") for f in definition["fields"]}