refactor: flatten monorepo to single web package (#12)

Flatten the pnpm monorepo (apps/web + packages/*) into a single web package at the repo root.

- Move app/lib/components/scripts/public to root; drop apps/web and packages/* wrappers
- Rewrite tsconfig paths (@infiplot/*) to ./lib/*; turbopack.root = __dirname
- Update Vercel (no root-directory) and Cloudflare (pnpm build:cf at root) deploy paths
- Regenerate pnpm-lock.yaml to drop stale workspace importers
- Bump engines.node to >=22 to match wrangler

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tsconfig.json

@@ -0,0 +1,56 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "lib": [
+      "ES2022",
+      "DOM",
+      "DOM.Iterable"
+    ],
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "esModuleInterop": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noUncheckedIndexedAccess": true,
+    "verbatimModuleSyntax": false,
+    "jsx": "react-jsx",
+    "noEmit": true,
+    "incremental": true,
+    "plugins": [
+      {
+        "name": "next"
+      }
+    ],
+    "paths": {
+      "@/*": [
+        "./*"
+      ],
+      "@infiplot/engine": [
+        "./lib/engine/index.ts"
+      ],
+      "@infiplot/ai-client": [
+        "./lib/ai-client/index.ts"
+      ],
+      "@infiplot/tts-client": [
+        "./lib/tts-client/index.ts"
+      ],
+      "@infiplot/types": [
+        "./lib/types/index.ts"
+      ]
+    },
+    "allowJs": true
+  },
+  "include": [
+    "next-env.d.ts",
+    "**/*.ts",
+    "**/*.tsx",
+    ".next/types/**/*.ts",
+    ".next/dev/types/**/*.ts"
+  ],
+  "exclude": [
+    "node_modules"
+  ]
+}