Initial scaffold: full-stack RackMapper application

Complete project scaffold with working auth, REST API, Prisma/SQLite
schema, Docker config, and React frontend for both Rack Planner and
Service Mapper modules. Both server and client pass TypeScript strict
mode with zero errors. Initial migration applied.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/src/components/mapper/nodes/DatabaseNode.tsx

@@ -0,0 +1,18 @@
+import { memo } from 'react';
+import { Handle, Position, type NodeProps } from '@xyflow/react';
+import { Database } from 'lucide-react';
+
+export const DatabaseNode = memo(({ data, selected }: NodeProps) => {
+  const label = (data as { label?: string }).label ?? 'Database';
+  return (
+    <div className={`min-w-[140px] bg-slate-800 border rounded-lg shadow-lg overflow-hidden ${selected ? 'ring-2 ring-teal-500 border-teal-500' : 'border-teal-700'}`}>
+      <Handle type="target" position={Position.Top} className="!bg-teal-400 !border-teal-600" />
+      <div className="px-3 py-2 flex items-center gap-2">
+        <Database size={13} className="text-teal-400 shrink-0" />
+        <span className="text-xs font-medium text-slate-100 truncate">{label}</span>
+      </div>
+      <Handle type="source" position={Position.Bottom} className="!bg-teal-400 !border-teal-600" />
+    </div>
+  );
+});
+DatabaseNode.displayName = 'DatabaseNode';