feat: add engagement mixin for like/unlike/retweet/unretweet/bookmark

Adds a new mixin with programmatic engagement methods:
- like(tweetId) - FavoriteTweet
- unlike(tweetId) - UnfavoriteTweet
- retweet(tweetId) - CreateRetweet
- unretweet(tweetId) - DeleteRetweet
- bookmark(tweetId) - CreateBookmark

Implementation follows existing mixin patterns with:
- Shared performEngagementMutation() helper
- 404 retry with query ID refresh
- Returns BookmarkMutationResult for consistency

Also adds query IDs for the new operations to constants and
the update-query-ids script.

Includes 9 tests covering success cases, error handling, and retry logic.

src/lib/twitter-client-engagement.ts

@@ -0,0 +1,116 @@
+import type { AbstractConstructor, Mixin, TwitterClientBase } from './twitter-client-base.js';
+import { type OperationName, TWITTER_API_BASE, TWITTER_GRAPHQL_POST_URL } from './twitter-client-constants.js';
+import type { BookmarkMutationResult } from './twitter-client-types.js';
+
+export interface TwitterClientEngagementMethods {
+  /** Like a tweet. */
+  like(tweetId: string): Promise<BookmarkMutationResult>;
+  /** Remove a like from a tweet. */
+  unlike(tweetId: string): Promise<BookmarkMutationResult>;
+  /** Retweet a tweet. */
+  retweet(tweetId: string): Promise<BookmarkMutationResult>;
+  /** Remove a retweet. */
+  unretweet(tweetId: string): Promise<BookmarkMutationResult>;
+  /** Bookmark a tweet. */
+  bookmark(tweetId: string): Promise<BookmarkMutationResult>;
+}
+
+export function withEngagement<TBase extends AbstractConstructor<TwitterClientBase>>(
+  Base: TBase,
+): Mixin<TBase, TwitterClientEngagementMethods> {
+  abstract class TwitterClientEngagement extends Base {
+    // biome-ignore lint/complexity/noUselessConstructor lint/suspicious/noExplicitAny: TS mixin constructor requirement.
+    constructor(...args: any[]) {
+      super(...args);
+    }
+
+    private async performEngagementMutation(
+      operationName: OperationName,
+      tweetId: string,
+    ): Promise<BookmarkMutationResult> {
+      const variables = { tweet_id: tweetId };
+      let queryId = await this.getQueryId(operationName);
+      let urlWithOperation = `${TWITTER_API_BASE}/${queryId}/${operationName}`;
+
+      const buildBody = () => JSON.stringify({ variables, queryId });
+      const buildHeaders = () => ({ ...this.getHeaders(), referer: `https://x.com/i/status/${tweetId}` });
+      let body = buildBody();
+
+      const parseResponse = async (response: Response): Promise<BookmarkMutationResult> => {
+        if (!response.ok) {
+          const text = await response.text();
+          return { success: false, error: `HTTP ${response.status}: ${text.slice(0, 200)}` };
+        }
+
+        const data = (await response.json()) as { errors?: Array<{ message: string }> };
+        if (data.errors && data.errors.length > 0) {
+          return { success: false, error: data.errors.map((e) => e.message).join(', ') };
+        }
+
+        return { success: true };
+      };
+
+      try {
+        let response = await this.fetchWithTimeout(urlWithOperation, {
+          method: 'POST',
+          headers: buildHeaders(),
+          body,
+        });
+
+        if (response.status === 404) {
+          await this.refreshQueryIds();
+          queryId = await this.getQueryId(operationName);
+          urlWithOperation = `${TWITTER_API_BASE}/${queryId}/${operationName}`;
+          body = buildBody();
+
+          response = await this.fetchWithTimeout(urlWithOperation, {
+            method: 'POST',
+            headers: buildHeaders(),
+            body,
+          });
+
+          if (response.status === 404) {
+            const retry = await this.fetchWithTimeout(TWITTER_GRAPHQL_POST_URL, {
+              method: 'POST',
+              headers: buildHeaders(),
+              body,
+            });
+
+            return parseResponse(retry);
+          }
+        }
+
+        return parseResponse(response);
+      } catch (error) {
+        return { success: false, error: error instanceof Error ? error.message : String(error) };
+      }
+    }
+
+    /** Like a tweet. */
+    async like(tweetId: string): Promise<BookmarkMutationResult> {
+      return this.performEngagementMutation('FavoriteTweet', tweetId);
+    }
+
+    /** Remove a like from a tweet. */
+    async unlike(tweetId: string): Promise<BookmarkMutationResult> {
+      return this.performEngagementMutation('UnfavoriteTweet', tweetId);
+    }
+
+    /** Retweet a tweet. */
+    async retweet(tweetId: string): Promise<BookmarkMutationResult> {
+      return this.performEngagementMutation('CreateRetweet', tweetId);
+    }
+
+    /** Remove a retweet. */
+    async unretweet(tweetId: string): Promise<BookmarkMutationResult> {
+      return this.performEngagementMutation('DeleteRetweet', tweetId);
+    }
+
+    /** Bookmark a tweet. */
+    async bookmark(tweetId: string): Promise<BookmarkMutationResult> {
+      return this.performEngagementMutation('CreateBookmark', tweetId);
+    }
+  }
+
+  return TwitterClientEngagement;
+}