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>

docker.nix

@@ -0,0 +1,66 @@
+{ pkgs, pythonEnv, python }:
+
+let
+  # Build animaltrack as a package
+  animaltrack = python.pkgs.buildPythonApplication {
+    pname = "animaltrack";
+    version = "0.1.0";
+    src = ./.;
+    format = "pyproject";
+
+    nativeBuildInputs = [ python.pkgs.setuptools ];
+
+    propagatedBuildInputs = [ pythonEnv ];
+
+    doCheck = false;
+
+    # Don't wrap, we'll handle PATH manually
+    dontWrapPythonPrograms = true;
+  };
+in
+pkgs.dockerTools.buildImage {
+  name = "gitea.v.paler.net/ppetru/animaltrack";
+  tag = "latest";
+
+  copyToRoot = pkgs.buildEnv {
+    name = "animaltrack-env";
+    paths = with pkgs; [
+      # System utilities
+      busybox
+      bash
+      sqlite
+
+      # Python environment with all packages
+      pythonEnv
+
+      # Animaltrack application
+      animaltrack
+    ] ++ [
+      # Docker filesystem helpers
+      pkgs.dockerTools.usrBinEnv
+      pkgs.dockerTools.binSh
+      pkgs.dockerTools.fakeNss
+      pkgs.dockerTools.caCertificates
+    ];
+  };
+
+  runAsRoot = ''
+    #!${pkgs.stdenv.shell}
+    mkdir -p -m 1777 /tmp
+    mkdir -p /var/lib/animaltrack
+  '';
+
+  config = {
+    Env = [
+      "DB_PATH=/var/lib/animaltrack/animaltrack.db"
+      "PATH=${pkgs.lib.makeBinPath [ pkgs.busybox pkgs.bash pkgs.sqlite pythonEnv ]}"
+      "PYTHONPATH=${pythonEnv}/${pythonEnv.sitePackages}"
+      "PYTHONUNBUFFERED=1"
+    ];
+    ExposedPorts = {
+      "5000/tcp" = {};
+    };
+    Cmd = [ "sh" "-c" "animaltrack migrate && animaltrack serve" ];
+    WorkingDir = "/var/lib/animaltrack";
+  };
+}