fix: restart queue when a job is queued

When the worker queue drains, it sets is_running=false on the Queue
record. If a new job is then queued, the worker's loop skips it
entirely because is_running=false — the job sits frozen until the
user manually starts the queue.

Fix: always set is_running=true on the queue when a job is queued,
mirroring what the /api/queue/[queueID]/start route already does.
Also fixes the create-path which was creating the queue with
is_running=false, meaning a brand-new queue would also never start.

ui/src/app/api/jobs/[jobID]/start/route.ts

@@ -0,0 +1,65 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { PrismaClient } from '@prisma/client';
+
+const prisma = new PrismaClient();
+
+export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
+  const { jobID } = await params;
+
+  const job = await prisma.job.findUnique({
+    where: { id: jobID },
+  });
+
+  if (!job) {
+    return NextResponse.json({ error: 'Job not found' }, { status: 404 });
+  }
+
+  // get highest queue position
+  const highestQueuePosition = await prisma.job.aggregate({
+    _max: {
+      queue_position: true,
+    },
+  });
+  const newQueuePosition = (highestQueuePosition._max.queue_position || 0) + 1000;
+
+  await prisma.job.update({
+    where: { id: jobID },
+    data: { queue_position: newQueuePosition },
+  });
+
+  // make sure the queue exists and is running
+  const queue = await prisma.queue.findFirst({
+    where: {
+      gpu_ids: job.gpu_ids,
+    },
+  });
+
+  // if queue doesn't exist, create it and start it
+  if (!queue) {
+    await prisma.queue.create({
+      data: {
+        gpu_ids: job.gpu_ids,
+        is_running: true,
+      },
+    });
+  } else {
+    // ensure the queue is running so the worker picks up the new job
+    await prisma.queue.update({
+      where: { id: queue.id },
+      data: { is_running: true },
+    });
+  }
+
+  await prisma.job.update({
+    where: { id: jobID },
+    data: {
+      status: 'queued',
+      stop: false,
+      return_to_queue: false,
+      info: 'Job queued',
+    },
+  });
+
+  // Return the response immediately
+  return NextResponse.json(job);
+}