feat: initial project setup with implementation plan

- Add PLAN.md with 40-step checklist across 10 phases
- Add CLAUDE.md with project-specific instructions
- Set up nix flake with FastHTML/MonsterUI dependencies
- Create Python package skeleton (src/animaltrack)
- Vendor FastHTML and MonsterUI documentation
- Add Docker build configuration

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/python-fasthtml.nix

@@ -0,0 +1,51 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchPypi,
+  setuptools,
+  fastcore,
+  python-dateutil,
+  starlette,
+  oauthlib,
+  itsdangerous,
+  uvicorn,
+  httpx,
+  fastlite,
+  python-multipart,
+  beautifulsoup4,
+}:
+
+buildPythonPackage rec {
+  pname = "python-fasthtml";
+  version = "0.12.35";
+  pyproject = true;
+
+  src = fetchPypi {
+    pname = "python_fasthtml";
+    inherit version;
+    hash = "sha256:15iq7zykqa1i7mkir2wzg0js2dvjplarq1jzb9igj61qb5f25p1l";
+  };
+
+  build-system = [ setuptools ];
+
+  dependencies = [
+    fastcore
+    python-dateutil
+    starlette
+    oauthlib
+    itsdangerous
+    uvicorn
+    httpx
+    fastlite
+    python-multipart
+    beautifulsoup4
+  ];
+
+  doCheck = false;
+
+  meta = {
+    description = "FastHTML - Modern web applications in pure Python";
+    homepage = "https://github.com/AnswerDotAI/fasthtml";
+    license = lib.licenses.asl20;
+  };
+}