Full mobile responsive (320px) and tablet (768px) support across all templates

- All text-[20rem] background text → text-[8rem] md:text-[20rem]
- All text-8xl → text-5xl md:text-8xl
- All text-5xl emojis → text-3xl md:text-5xl
- edit_event: w-full md:w-[80%], poster column w-full lg:w-[350px]
- account/index: tab bar overflow-x-auto, events table overflow-x-auto
- admin/events: table overflow-x-auto
- register: tab buttons overflow-x-auto
- error 404/500: responsive padding p-6 md:p-12
- base footer: flex-col sm:flex-row for bottom bar
- Add PWA bundle (spomky-labs/pwa-bundle) with composer require files

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

symfony.lock

@@ -120,6 +120,18 @@
             "bin/phpunit"
         ]
     },
+    "spomky-labs/pwa-bundle": {
+        "version": "1.5",
+        "recipe": {
+            "repo": "github.com/symfony/recipes-contrib",
+            "branch": "main",
+            "version": "1.3",
+            "ref": "ac33d9498ab25856f16d1d7df9ad4b9b0cad066d"
+        },
+        "files": [
+            "config/packages/pwa.yaml"
+        ]
+    },
     "stripe/stripe-php": {
         "version": "19.4",
         "recipe": {
@@ -138,6 +150,21 @@
             "ref": "9648db3ecae5c8a6b1a5f74715d3907124348815"
         }
     },
+    "symfony/asset-mapper": {
+        "version": "8.0",
+        "recipe": {
+            "repo": "github.com/symfony/recipes",
+            "branch": "main",
+            "version": "6.4",
+            "ref": "5ad1308aa756d58f999ffbe1540d1189f5d7d14a"
+        },
+        "files": [
+            "assets/app.js",
+            "assets/styles/app.css",
+            "config/packages/asset_mapper.yaml",
+            "importmap.php"
+        ]
+    },
     "symfony/console": {
         "version": "8.0",
         "recipe": {