feat(hosts): generate unique 8-digit asset ID

Add a Generate button to the host create dialog that fetches a random
8-digit asset ID from the new GET /hosts/generate-asset-id endpoint.
The service retries against the unique index so the returned ID is
guaranteed unused. Edit mode hides the button.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/api/src/controllers/hosts.ts

@@ -29,6 +29,15 @@ export async function get(req: Request<{ id: string }>, res: Response, next: Nex
   }
 }
 
+export async function generateAssetId(_req: Request, res: Response, next: NextFunction) {
+  try {
+    const result = await prisma.$transaction((tx) => svc.generateAssetId(tx));
+    res.json(result);
+  } catch (err) {
+    next(err);
+  }
+}
+
 export async function create(req: Request, res: Response, next: NextFunction) {
   try {
     const input = req.validated!.body as CreateHostRequest;

apps/api/src/routes/hosts.ts

@@ -13,6 +13,7 @@ const router = Router();
 
 router.get('/', requireAuth, validate('query', HostListQuery), ctrl.list);
 router.post('/', requireAuth, requireRole('ADMIN'), validate('body', CreateHostRequest), ctrl.create);
+router.get('/generate-asset-id', requireAuth, requireRole('ADMIN'), ctrl.generateAssetId);
 router.get('/:id', requireAuth, ctrl.get);
 router.get('/:id/deployed-parts', requireAuth, ctrl.listDeployedParts);
 router.get('/:id/timeline', requireAuth, validate('query', HostTimelineQuery), ctrl.getTimeline);

apps/api/src/services/hosts.ts

@@ -41,6 +41,18 @@ export function get(tx: Tx, id: string) {
   return tx.host.findUnique({ where: { id } });
 }
 
+// Random 8-digit asset ID (zero-padded) that isn't already taken. With ~100M
+// possible values and only hundreds of hosts in practice, collisions are rare
+// — we still retry a few times to be safe, then bail instead of looping forever.
+export async function generateAssetId(tx: Tx): Promise<{ assetId: string }> {
+  for (let attempt = 0; attempt < 20; attempt++) {
+    const candidate = String(Math.floor(Math.random() * 100_000_000)).padStart(8, '0');
+    const existing = await tx.host.findUnique({ where: { assetId: candidate }, select: { id: true } });
+    if (!existing) return { assetId: candidate };
+  }
+  throw errors.conflict('Could not generate a unique asset ID');
+}
+
 export function listDeployedParts(tx: Tx, hostId: string) {
   return tx.part.findMany({
     where: { hostId, state: 'DEPLOYED' },

apps/web/src/components/hosts/HostFormDialog.tsx

@@ -3,7 +3,7 @@ import { useForm } from 'react-hook-form';
 import { zodResolver } from '@hookform/resolvers/zod';
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 import { z } from 'zod';
-import { Loader2 } from 'lucide-react';
+import { Loader2, Sparkles } from 'lucide-react';
 import { toast } from 'sonner';
 import { HostStack, HostState } from '@vector/shared';
 import {
@@ -28,7 +28,7 @@ import {
   SelectValue,
   Textarea,
 } from '@vector/ui';
-import { createHost, updateHost } from '../../lib/api/hosts.js';
+import { createHost, generateHostAssetId, updateHost } from '../../lib/api/hosts.js';
 import { ApiRequestError } from '../../lib/api/client.js';
 import { queryKeys } from '../../lib/queryKeys.js';
 import type { Host } from '../../lib/api/types.js';
@@ -88,6 +88,15 @@ export function HostFormDialog({ open, onOpenChange, host }: HostFormDialogProps
     });
   }, [open, host, form]);
 
+  const generateMutation = useMutation({
+    mutationFn: () => generateHostAssetId(),
+    onSuccess: ({ assetId }) => {
+      form.setValue('assetId', assetId, { shouldDirty: true, shouldValidate: true });
+    },
+    onError: (err) =>
+      toast.error(err instanceof ApiRequestError ? err.body.message : 'Generate failed'),
+  });
+
   const mutation = useMutation({
     mutationFn: async (values: Values) => {
       if (editing && host) {
@@ -136,9 +145,27 @@ export function HostFormDialog({ open, onOpenChange, host }: HostFormDialogProps
               render={({ field }) => (
                 <FormItem>
                   <FormLabel>Asset ID</FormLabel>
+                  <div className="flex gap-2">
                     <FormControl>
                       <Input autoFocus placeholder="e.g. ASSET-001" {...field} />
                     </FormControl>
+                    {!editing && (
+                      <Button
+                        type="button"
+                        variant="outline"
+                        onClick={() => generateMutation.mutate()}
+                        disabled={generateMutation.isPending}
+                        title="Generate an unused 8-digit asset ID"
+                      >
+                        {generateMutation.isPending ? (
+                          <Loader2 className="h-4 w-4 animate-spin" />
+                        ) : (
+                          <Sparkles className="h-4 w-4" />
+                        )}
+                        Generate
+                      </Button>
+                    )}
+                  </div>
                   <FormMessage />
                 </FormItem>
               )}

apps/web/src/lib/api/hosts.ts

@@ -42,3 +42,8 @@ export async function updateHost(id: string, input: UpdateHostRequest): Promise<
 export async function deleteHost(id: string): Promise<void> {
   await api.delete(`/hosts/${id}`);
 }
+
+export async function generateHostAssetId(): Promise<{ assetId: string }> {
+  const res = await api.get<{ assetId: string }>('/hosts/generate-asset-id');
+  return res.data;
+}