feat: add user job listing and summary helpers for dashboard flows

src/lib/engine.js

@@ -120,6 +120,29 @@ class XArtAudioEngine {
     return this.jobs.get(jobId) || null;
   }
 
+  listJobsForUser(userId) {
+    if (!userId) {
+      return [];
+    }
+
+    return Array.from(this.jobs.values())
+      .filter((job) => job.callerUserId === userId)
+      .sort((a, b) => Number(b.id) - Number(a.id));
+  }
+
+  getUserSummary(userId) {
+    const jobs = this.listJobsForUser(userId);
+    const completed = jobs.filter((job) => job.status === "completed").length;
+    const totalCreditsSpent = jobs.reduce((sum, job) => sum + job.creditsCharged, 0);
+
+    return {
+      balance: this.getWalletBalance(userId),
+      totalJobs: jobs.length,
+      completedJobs: completed,
+      totalCreditsSpent,
+    };
+  }
+
   getAsset(assetId) {
     return this.assets.get(String(assetId)) || null;
   }