feat: populate quotedCids when publishing replies with quote references

Parse reply content for >>{postNumber} references, resolve post numbers to CIDs via usePostNumberStore, and include resolved CIDs in publishCommentOptions when publishing. Extracted quote handling into reply-quote-utils.ts for testability and clarity.

src/lib/utils/reply-quote-utils.ts

@@ -0,0 +1,23 @@
+import { QUOTE_NUMBER_REGEX } from './url-utils';
+
+export const getQuotedCidsFromContent = (content: string | undefined, numberToCid: Record<number, string>) => {
+  if (!content) return undefined;
+  const cids = new Set<string>();
+  for (const match of content.matchAll(new RegExp(QUOTE_NUMBER_REGEX.source, 'g'))) {
+    const num = parseInt(match[1], 10);
+    const cid = numberToCid[num];
+    if (cid) cids.add(cid);
+  }
+  return cids.size > 0 ? [...cids] : undefined;
+};
+
+export const mergeQuotedCids = (publishCommentOptions: Record<string, any> | undefined, quotedCids: string[] | undefined) => {
+  if (!publishCommentOptions || !quotedCids?.length) return publishCommentOptions;
+  const currentQuotedCids = publishCommentOptions.quotedCids ?? [];
+  const mergedQuotedCids = [...new Set([...currentQuotedCids, ...quotedCids])];
+
+  return {
+    ...publishCommentOptions,
+    quotedCids: mergedQuotedCids,
+  };
+};