feat: add seed scripts and AI worker

Adds scripts/seed.ts for fresh self-hosted installs, scripts/seed-tenant.ts for cloud provisioner use, and scripts/ai-worker.ts adapted from AHCR with improved theme prompts, name filtering, and WORKER_API_KEY guard. Installs tsx as a dev dependency.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -12,6 +12,7 @@
 		"check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch"
 	},
 	"devDependencies": {
+		"@playwright/test": "^1.58.2",
 		"@sveltejs/adapter-auto": "^7.0.0",
 		"@sveltejs/adapter-node": "^5.5.4",
 		"@sveltejs/kit": "^2.50.2",
@@ -22,8 +23,10 @@
 		"svelte": "^5.54.0",
 		"svelte-check": "^4.4.2",
 		"tailwindcss": "^4.2.2",
+		"tsx": "^4.21.0",
 		"typescript": "^5.9.3",
-		"vite": "^7.3.1"
+		"vite": "^7.3.1",
+		"vitest": "^4.1.2"
 	},
 	"dependencies": {
 		"@node-rs/argon2": "^2.0.2",