fix: four worker.rs bugs found during E2E testing

src/worker.rs

@@ -294,6 +294,8 @@ fn try_load_with_polling(
             Err(e) => {
                 tracing::error!(error = %e, "model load failed with non-recoverable error");
                 set_state(model_state, ModelState::Unloaded);
+                broadcast_event(model_event_tx, ModelEvent::ModelUnloaded);
+                fire_webhooks(webhook_registry, ModelEvent::ModelUnloaded, rt);
                 return None;
             }
         }
@@ -427,6 +429,7 @@ async fn run(
         };
 
         if job.status == JobStatus::Cancelled {
+            let _ = tokio::fs::remove_file(&audio_path_for(&job_id)).await;
             registry.remove(&job_id);
             continue;
         }
@@ -447,6 +450,15 @@ async fn run(
 
         let _ = tokio::fs::remove_file(&audio_path).await;
 
+        // Re-read from storage: the job may have been cancelled via DELETE /jobs/:id
+        // while process_job() was running. If so, discard the result entirely.
+        let current_status = storage.get(&job_id).await.map(|j| j.status).ok();
+        if current_status == Some(JobStatus::Cancelled) {
+            tracing::info!(job_id = %job_id, "job cancelled during inference — discarding result");
+            registry.remove(&job_id);
+            continue;
+        }
+
         match result {
             Ok((segments, language, duration_secs)) => {
                 job.status        = JobStatus::Done;
@@ -615,17 +627,20 @@ async fn process_job(
         let base  = (ci * 100 / n) as u8;
         let span  = (100usize / n).max(1) as u8;
 
-        let _ = progress_tx.send(ProgressEvent::Progress {
-            percent: base,
-            chunk:   ci + 1,
-            total:   n,
-        });
+        // Save progress to disk before emitting SSE — polling clients who respond
+        // immediately to the SSE event will then see consistent state.
         let mut snapshot = job.clone();
         snapshot.progress = base;
         if let Err(e) = storage.save(&snapshot).await {
             tracing::warn!(error = %e, "failed to persist mid-job progress");
         }
 
+        let _ = progress_tx.send(ProgressEvent::Progress {
+            percent: base,
+            chunk:   ci + 1,
+            total:   n,
+        });
+
         let tx        = progress_tx.clone();
         let chunk_num = ci + 1;
         let on_progress = Box::new(move |p: u8| {