fix: ai-jobs page empty list + missing Review button + no results in modal

Three bugs:

1. +page.server.ts returned an unawaited Promise — SvelteKit awaits it on
   the server anyway so data.jobs arrived as a plain AIJob[] on the client,
   not a Promise. The $effect calling .then() on an array silently failed,
   leaving jobs=[] and the table empty. Fixed by awaiting in the load fn.

2. +page.svelte $effect updated to assign data.jobs directly (plain array)
   instead of calling .then() on it.

3. handlers_textgen.go: final UpdateAIJob (payload+status write) used
   r.Context() which is cancelled when the SSE client disconnects. If the
   browser navigated away mid-job, results were silently dropped and the
   payload stayed as the initial {pattern} stub with no results array.
   Fixed by using context.Background() for the final write, matching the
   pattern already used in handlers_image.go.

ui/src/routes/admin/ai-jobs/+page.server.ts

@@ -6,8 +6,7 @@ export type { AIJob };
 
 export const load: PageServerLoad = async () => {
 	// Parent layout already guards admin role.
-	// Stream jobs so navigation is instant; list populates a moment later.
-	const jobs = listAIJobs().catch((e): AIJob[] => {
+	const jobs = await listAIJobs().catch((e): AIJob[] => {
 		log.warn('admin/ai-jobs', 'failed to load ai jobs', { err: String(e) });
 		return [];
 	});

ui/src/routes/admin/ai-jobs/+page.svelte

@@ -9,9 +9,9 @@
 
 	let jobs = $state<AIJob[]>([]);
 
-	// Resolve streamed promise on load and on server reloads (invalidateAll)
+	// data.jobs is a plain AIJob[] (resolved on server); re-sync on invalidateAll
 	$effect(() => {
-		data.jobs.then((resolved) => { jobs = resolved; });
+		jobs = data.jobs;
 	});
 
 	// ── Live-poll while any job is in-flight ─────────────────────────────────────