refactor: migrated packages to internal utility modules and removed external dependencies

- Implemented in-house, zero-dependency utility modules in `pi-utils` covering DOM manipulation, markdown parsing, templating, browser automation helpers, and terminal buffers.
- Migrated packages across the repository to consume the new internal utilities and `omptype` schema validators instead of external dependencies.
- Removed multiple external runtime and development dependencies including Zod, Marked, LRU cache, Turndown, and Puppeteer browser packages.

packages/stats/package.json

@@ -44,7 +44,6 @@
     "@oh-my-pi/pi-utils": "catalog:",
     "@tailwindcss/node": "catalog:",
     "chart.js": "catalog:",
-    "date-fns": "catalog:",
     "lucide-react": "catalog:",
     "react": "catalog:",
     "react-chartjs-2": "catalog:",
@@ -55,7 +54,6 @@
     "@types/bun": "catalog:",
     "@types/react": "catalog:",
     "@types/react-dom": "catalog:",
-    "linkedom": "catalog:",
     "postcss": "catalog:"
   },
   "engines": {