fix: worker detects deleted jobs and skips them

When a job is deleted from the database (e.g., by unregister),
the worker now checks if the job still exists before processing.
If the job no longer exists, it skips it instead of getting stuck.

This fixes the issue where unregistering a file would leave the
worker stuck trying to process a non-existent job.

src/worker/job_worker.rs

@@ -278,6 +278,13 @@ impl JobWorker {
     }
 
     async fn process_job(&self, job: crate::core::db::MonitorJob) -> Result<()> {
+        // Check if job still exists in database (may have been deleted by unregister)
+        let current_job = self.db.get_monitor_job_by_uuid(&job.uuid).await?;
+        if current_job.is_none() {
+            info!("Job {} no longer exists in database (possibly unregistered), skipping", job.uuid);
+            return Ok(());
+        }
+
         info!("Processing job: {} ({})", job.uuid, job.id);
 
         // Determine which processors to run based on job.processors field
@@ -1833,6 +1840,19 @@ impl JobWorker {
 
             // 🚀 P4 Trigger: TKG Build (Face + ASRX) → then Rule2 ingestion
             if has_face && has_asrx {
+                // Guard: only spawn TKG if nodes don't exist yet
+                let tkg_nodes_table = schema::table_name("tkg_nodes");
+                let tkg_exists: bool = sqlx::query_scalar::<_, i32>(&format!(
+                    "SELECT 1 FROM {tkg_nodes_table} WHERE file_uuid = $1 LIMIT 1"
+                ))
+                .bind(uuid)
+                .fetch_optional(self.db.pool())
+                .await?
+                .unwrap_or(0) > 0;
+
+                if tkg_exists {
+                    info!("✅ TKG already built for {}, skipping", uuid);
+                } else {
                     info!("📝 Prerequisites met for TKG Build. Starting graph construction...");
                     let db_clone = self.db.clone();
                     let redis_clone = self.redis.clone();
@@ -1867,6 +1887,7 @@ impl JobWorker {
                         }
                     });
                 }
+            }
 
             if !Self::ingestion_complete(self.db.pool(), uuid, job_processors).await {
                 info!(