refactor(glossaire): stabiliser le moteur de navigation intelligente

Reviewed-on: #329

src/lib/glossary.ts

@@ -510,13 +510,19 @@ export function getGlossarySmartNavigation(
 ): GlossarySmartNavigation {
   const currentSlug = slugOfGlossaryEntry(currentEntry);
   const rawNavigation = currentEntry.data.navigation;
-  const defaultNavigation = GLOSSARY_NAV_DEFAULTS[familyOf(currentEntry)];
+  const defaultNavigation = GLOSSARY_NAV_DEFAULTS[familyOf(currentEntry)] ?? {};
 
-  const navigationSource = rawNavigation ?? {
-    primaryNext: undefined,
-    primaryReason: undefined,
-    paths: defaultNavigation ?? {},
-    flows: {},
+  const navigationSource = {
+    primaryNext: rawNavigation?.primaryNext,
+    primaryReason: rawNavigation?.primaryReason,
+    paths: {
+      understand: rawNavigation?.paths?.understand ?? defaultNavigation.understand ?? [],
+      deepen: rawNavigation?.paths?.deepen ?? defaultNavigation.deepen ?? [],
+      compare: rawNavigation?.paths?.compare ?? defaultNavigation.compare ?? [],
+      apply: rawNavigation?.paths?.apply ?? defaultNavigation.apply ?? [],
+    },
+    flows: rawNavigation?.flows ?? {},
+    relationWeights: rawNavigation?.relationWeights ?? {},
   };
 
   const primaryNext = resolveGlossaryEntriesInSourceOrder(