refactor: Unify streamId and conversationId handling for improved job management

- Updated ResumableAgentController and AgentController to generate conversationId upfront, ensuring it matches streamId for consistency.
- Simplified job creation and metadata management by removing redundant conversationId updates from callbacks.
- Refactored abortMiddleware and related methods to utilize the unified streamId/conversationId approach, enhancing clarity in job handling.
- Removed deprecated methods from GenerationJobManager and InMemoryJobStore, streamlining the codebase and improving maintainability.

packages/api/src/stream/GenerationJobManager.ts

@@ -260,21 +260,6 @@ class GenerationJobManagerClass {
     return this.buildJobFacade(streamId, jobData, runtime);
   }
 
-  /**
-   * Find an active job by conversationId.
-   */
-  async getJobByConversation(conversationId: string): Promise<t.GenerationJob | undefined> {
-    const jobData = await this.jobStore.getJobByConversation(conversationId);
-    if (!jobData) {
-      return undefined;
-    }
-    const runtime = this.runtimeState.get(jobData.streamId);
-    if (!runtime) {
-      return undefined;
-    }
-    return this.buildJobFacade(jobData.streamId, jobData, runtime);
-  }
-
   /**
    * Check if a job exists.
    */
@@ -395,21 +380,6 @@ class GenerationJobManagerClass {
       .trim();
   }
 
-  /**
-   * Abort a job by conversationId (for abort middleware).
-   * Returns abort result with all data needed for token spending and message saving.
-   */
-  async abortByConversation(conversationId: string): Promise<AbortResult> {
-    const jobData = await this.jobStore.getJobByConversation(conversationId);
-    if (!jobData) {
-      logger.debug(
-        `[GenerationJobManager] No active job found for conversation: ${conversationId}`,
-      );
-      return { success: false, jobData: null, content: [], text: '', finalEvent: null };
-    }
-    return this.abortJob(jobData.streamId);
-  }
-
   /**
    * Subscribe to a job's event stream.
    *