feat: PhotoPrism M0 bring-up — compose stack, web client, sidecar, migrate

Replace the legacy mule-image backend with PhotoPrism plus a thin
SvelteKit client and a Node sidecar for endpoints PhotoPrism doesn't
expose (file rename), and add a two-phase migrator (metadata via PUT,
heaps → albums) for the existing Postgres library.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/vite.config.ts

@@ -0,0 +1,25 @@
+import { sveltekit } from '@sveltejs/kit/vite';
+import tailwindcss from '@tailwindcss/vite';
+import { defineConfig } from 'vite';
+
+export default defineConfig({
+	plugins: [tailwindcss(), sveltekit()],
+	server: {
+		proxy: {
+			// mule-sidecar — file rename + (future) folder mutations and
+			// per-user heap sharing. Matched BEFORE `/api/*` so PhotoPrism
+			// doesn't swallow these paths.
+			'/api/sidecar': {
+				target: 'http://localhost:8000',
+				changeOrigin: false,
+				rewrite: (p) => p
+			},
+			// PhotoPrism REST + WebSocket.
+			'/api': {
+				target: 'http://localhost:2342',
+				changeOrigin: true,
+				ws: true
+			}
+		}
+	}
+});