feat: flag accounts Reddit considers unestablished and re-test them

New accounts cannot start chats until Reddit considers them established.
Until now the bot would burn a candidate on every invitation Reddit was
always going to reject, with nothing in the dashboard explaining why the
account looked idle.

Two signals feed the verdict. A periodic profile check reads the
account's own age, karma and email verification from about.json and
compares them against configurable thresholds — that is what flags a
brand new account before it wastes anything. A rejected invitation is
authoritative: Reddit has told us directly, so the account is held out of
sending with a backoff that doubles per rejection, and a delivered
invitation clears the flag outright.

An unestablished account takes no new posts (canAcceptPost), raises an
attention item, reports an `unestablished` sending state, and shows its
age/karma evidence on the Accounts page. An unchecked account is always
allowed through, so a first run is never blocked.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/reddit/api.ts

@@ -16,8 +16,34 @@ const RedditUserAboutResponseSchema = z.object({
   }),
 });
 
+/**
+ * The subset of `/user/<name>/about.json` that says how established an account
+ * is. `has_verified_email` is only returned for the requesting user's own
+ * profile, so it stays nullable for anyone else.
+ */
+const RedditAccountProfileResponseSchema = z.object({
+  data: z.object({
+    created_utc: z.number().optional(),
+    link_karma: z.number().optional(),
+    comment_karma: z.number().optional(),
+    total_karma: z.number().optional(),
+    has_verified_email: z.boolean().nullish(),
+    is_suspended: z.boolean().optional(),
+  }),
+});
+
 export type RedditUserAccountStatus = 'active' | 'suspended' | 'deleted';
 
+export interface RedditAccountProfile {
+  /** Account creation time in epoch milliseconds. */
+  createdAt: number | null;
+  linkKarma: number | null;
+  commentKarma: number | null;
+  totalKarma: number | null;
+  hasVerifiedEmail: boolean | null;
+  isSuspended: boolean;
+}
+
 export class RedditRateLimitError extends Error {
   constructor(public readonly retryAfterMs: number) {
     const retryAfterSeconds = Math.ceil(retryAfterMs / 1000);
@@ -273,6 +299,42 @@ export class RedditApiClient {
     }
   }
 
+  /**
+   * Age, karma and email-verification for one account. Used to judge whether
+   * one of our own accounts is established enough for Reddit to let it start
+   * chats. Returns null when the profile no longer exists.
+   */
+  async getAccountProfile(username: string): Promise<RedditAccountProfile | null> {
+    const cookieHeader = await this.getCookieHeader();
+    const headers: Record<string, string> = {};
+    if (cookieHeader) headers.Cookie = cookieHeader;
+
+    try {
+      const response = await this.scheduleRequest(() => this.client.get(
+        `/user/${encodeURIComponent(username)}/about.json`,
+        { params: { raw_json: 1 }, headers },
+      ));
+      const { data } = RedditAccountProfileResponseSchema.parse(response.data);
+      const totalKarma = data.total_karma
+        ?? (data.link_karma === undefined && data.comment_karma === undefined
+          ? undefined
+          : (data.link_karma ?? 0) + (data.comment_karma ?? 0));
+      return {
+        createdAt: data.created_utc === undefined ? null : Math.round(data.created_utc * 1000),
+        linkKarma: data.link_karma ?? null,
+        commentKarma: data.comment_karma ?? null,
+        totalKarma: totalKarma ?? null,
+        hasVerifiedEmail: data.has_verified_email ?? null,
+        isSuspended: data.is_suspended === true,
+      };
+    } catch (error) {
+      if (axios.isAxiosError(error) && error.response?.status === 404) return null;
+      const rateLimitError = this.toRateLimitError(error);
+      if (rateLimitError) throw rateLimitError;
+      throw error;
+    }
+  }
+
   async getNewPosts(subreddit: string, limit = 25, type: 'image' | 'chat' = 'image'): Promise<RedditPost[]> {
     try {
       const cookieHeader = await this.getCookieHeader();