feat: persist settings and enrich conversation context

src/reddit/api.ts

@@ -8,6 +8,7 @@ export interface RedditPost {
   name: string; // fullname like "t3_xxxxx"
   subreddit: string;
   author: string;
+  author_fullname?: string; // account fullname like "t2_xxxxx"
   title: string;
   url: string;
   permalink: string;
@@ -83,6 +84,26 @@ export class RedditApiClient {
     }
   }
 
+  /** Resolve a Reddit username through the authenticated browser session. */
+  async resolveUsernameToT2(username: string): Promise<string | null> {
+    const cookieHeader = await this.getCookieHeader();
+    const headers: Record<string, string> = {};
+    if (cookieHeader) headers.Cookie = cookieHeader;
+
+    try {
+      const response = await this.client.get(
+        `/user/${encodeURIComponent(username)}/about.json`,
+        { params: { raw_json: 1 }, headers },
+      );
+      const id = response.data?.data?.id;
+      if (typeof id !== 'string' || id.length === 0) return null;
+      return id.startsWith('t2_') ? id : `t2_${id}`;
+    } catch (error) {
+      if (axios.isAxiosError(error) && error.response?.status === 404) return null;
+      throw error;
+    }
+  }
+
   async getNewPosts(subreddit: string, limit = 25, type: 'image' | 'chat' = 'image'): Promise<RedditPost[]> {
     try {
       const cookieHeader = await this.getCookieHeader();