Migrate harness from in-memory stores to CloudNativePG

Replace all in-memory Map-backed stores (credentials, models, agents,
tasks, iterations, usage) with Drizzle ORM queries against the
homelab-pg PostgreSQL cluster. All store functions are now async.

- Add 6 harness_* tables to @homelab/db schema
- Generate and apply initial Drizzle migration
- Add lazy DB connection proxy to avoid build-time errors
- Wire DATABASE_URL from sealed secret into harness deployment
- Update all API routes, orchestrator, executor, and boot to await
  async store operations

apps/harness/src/app/api/models/curated/route.ts

@@ -11,20 +11,20 @@ import {
 
 export async function GET(request: NextRequest) {
   const enabledOnly = request.nextUrl.searchParams.get("enabled") === "true";
-  return NextResponse.json(enabledOnly ? getEnabledModels() : getCuratedModels());
+  return NextResponse.json(enabledOnly ? await getEnabledModels() : await getCuratedModels());
 }
 
 export async function POST(request: NextRequest) {
   const body = await request.json();
 
   if (body.action === "toggle" && body.id) {
-    const result = toggleModelEnabled(body.id);
+    const result = await toggleModelEnabled(body.id);
     if (!result) return NextResponse.json({ error: "not found" }, { status: 404 });
     return NextResponse.json(result);
   }
 
   if (body.action === "update-cost" && body.id) {
-    const result = updateModelCost(body.id, body.costPer1kInput, body.costPer1kOutput);
+    const result = await updateModelCost(body.id, body.costPer1kInput, body.costPer1kOutput);
     if (!result) return NextResponse.json({ error: "not found" }, { status: 404 });
     return NextResponse.json(result);
   }
@@ -43,12 +43,12 @@ export async function POST(request: NextRequest) {
     costPer1kOutput: body.costPer1kOutput,
   };
 
-  return NextResponse.json(upsertCuratedModel(model), { status: 201 });
+  return NextResponse.json(await upsertCuratedModel(model), { status: 201 });
 }
 
 export async function DELETE(request: NextRequest) {
   const id = request.nextUrl.searchParams.get("id");
   if (!id) return NextResponse.json({ error: "id required" }, { status: 400 });
-  removeCuratedModel(id);
+  await removeCuratedModel(id);
   return NextResponse.json({ ok: true });
 }