chore(deploy): add Dockerfile and nginx config for Coolify SPA hosting

Multi-stage build: node:22-alpine + pnpm builds, nginx:1.27-alpine
serves. VITE_* env vars are passed as build args because Vite inlines
them into the JS bundle at build time. nginx config does SPA fallback,
caches /assets/* immutably, and forces no-store on sw.js/index.html so
PWA updates propagate.

nginx.conf

@@ -0,0 +1,59 @@
+server {
+    listen       80;
+    server_name  _;
+
+    root   /usr/share/nginx/html;
+    index  index.html;
+
+    # Compression
+    gzip            on;
+    gzip_comp_level 5;
+    gzip_min_length 256;
+    gzip_proxied    any;
+    gzip_vary       on;
+    gzip_types
+        application/javascript
+        application/json
+        application/manifest+json
+        application/wasm
+        application/xml
+        font/woff
+        font/woff2
+        image/svg+xml
+        text/css
+        text/plain;
+
+    # Vite emits hashed file names under /assets/ — cache hard
+    location /assets/ {
+        access_log off;
+        add_header Cache-Control "public, max-age=31536000, immutable";
+        try_files $uri =404;
+    }
+
+    # PWA control surfaces — never cache, so updates propagate
+    location = /sw.js {
+        add_header Cache-Control "no-store";
+        try_files $uri =404;
+    }
+    location = /registerSW.js {
+        add_header Cache-Control "no-store";
+        try_files $uri =404;
+    }
+    location = /manifest.webmanifest {
+        add_header Cache-Control "no-store";
+        types { } default_type application/manifest+json;
+        try_files $uri =404;
+    }
+
+    # Workbox precache + sourcemap helpers
+    location ~* ^/workbox-.*\.js$ {
+        add_header Cache-Control "public, max-age=31536000, immutable";
+        try_files $uri =404;
+    }
+
+    # SPA fallback — every other path serves index.html (no cache)
+    location / {
+        add_header Cache-Control "no-store";
+        try_files $uri $uri/ /index.html;
+    }
+}