Add PWA manifest, app icons, and favicon

D20-themed icon in app color scheme for home screen installation,
favicon, and apple-touch-icon. Standalone display mode makes the
app feel native when launched from home screen.

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

apps/web/public/manifest.json

@@ -0,0 +1,21 @@
+{
+	"name": "Initiative Tracker",
+	"short_name": "Initiative",
+	"description": "D&D combat initiative tracker",
+	"start_url": "/",
+	"display": "standalone",
+	"background_color": "#0e1a2e",
+	"theme_color": "#0e1a2e",
+	"icons": [
+		{
+			"src": "/icon-192.png",
+			"sizes": "192x192",
+			"type": "image/png"
+		},
+		{
+			"src": "/icon-512.png",
+			"sizes": "512x512",
+			"type": "image/png"
+		}
+	]
+}