feat(launch): waitlist page, raw-WebGPU hero, supabase + vercel infra

The July 14 launch surface, previously uncommitted:
- /dashboard/launch raw-WebGPU particle "memory brain" hero (RawVestigeEngine,
  NeuralWordmark, dendrite sign) + DOM waitlist overlay with share/referral.
- Supabase waitlist client + migrations + welcome edge function; legacy waitlist
  archived under supabase/legacy.
- vercel.json deploy config, root-redirect env wiring, base-path config,
  graph-only route, Playwright launch verifiers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

vercel.json

@@ -0,0 +1,47 @@
+{
+	"$schema": "https://openapi.vercel.sh/vercel.json",
+	"framework": null,
+	"installCommand": "pnpm install --frozen-lockfile",
+	"buildCommand": "VESTIGE_BASE_PATH= VITE_ROOT_REDIRECT=/launch pnpm --filter @vestige/dashboard build",
+	"outputDirectory": "apps/dashboard/build",
+	"cleanUrls": true,
+	"trailingSlash": false,
+	"headers": [
+		{
+			"source": "/_app/immutable/(.*)",
+			"headers": [
+				{
+					"key": "Cache-Control",
+					"value": "public, max-age=31536000, immutable"
+				}
+			]
+		},
+		{
+			"source": "/((?!_app/immutable/).*)",
+			"headers": [
+				{
+					"key": "Cache-Control",
+					"value": "public, max-age=0, must-revalidate"
+				}
+			]
+		}
+	],
+	"redirects": [
+		{
+			"source": "/dashboard/launch",
+			"destination": "/launch",
+			"permanent": false
+		},
+		{
+			"source": "/dashboard/launch/:path*",
+			"destination": "/launch",
+			"permanent": false
+		}
+	],
+	"rewrites": [
+		{
+			"source": "/((?!_app/|favicon\\.svg|manifest\\.json|robots\\.txt|.*\\..*).*)",
+			"destination": "/200.html"
+		}
+	]
+}