fix: getThoughtThread parses flat array and builds nested tree — backend returns Vec not nested object

thoughts-frontend/lib/api.ts

@@ -243,8 +243,22 @@ export const deleteThought = (thoughtId: string, token: string) =>
 export const getThoughtById = (thoughtId: string, token: string | null) =>
   apiFetch(`/thoughts/${thoughtId}`, {}, ThoughtSchema, token);
 
-export const getThoughtThread = (thoughtId: string, token: string | null) =>
-  apiFetch(`/thoughts/${thoughtId}/thread`, {}, ThoughtThreadSchema, token);
+export const getThoughtThread = async (thoughtId: string, token: string | null): Promise<ThoughtThread> => {
+  const thoughts = await apiFetch(`/thoughts/${thoughtId}/thread`, {}, z.array(ThoughtSchema), token);
+  type T = z.infer<typeof ThoughtSchema>;
+  const repliesMap: Record<string, T[]> = {};
+  for (const t of thoughts) {
+    if (t.replyToId) {
+      (repliesMap[t.replyToId] ??= []).push(t);
+    }
+  }
+  function build(t: T): ThoughtThread {
+    return { ...t, replies: (repliesMap[t.id] ?? []).map(build) };
+  }
+  const root = thoughts.find((t) => t.id === thoughtId) ?? thoughts[0];
+  if (!root) throw new Error("Thread not found");
+  return build(root);
+};
 
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