feat(tg-fitness-bot): add telegram fitness bot with web app

Telegram workout tracker bot with Mini App web UI, SQLite database,
API server, and cloudflared tunnel support.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

telegram-fitness-bot/flake.nix

@@ -0,0 +1,87 @@
+{
+  description = "Telegram Fitness Bot — Mini App for tracking gym workouts";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        python = pkgs.python3;
+
+        pythonEnv = python.withPackages (ps: with ps; [
+          python-telegram-bot
+          aiohttp
+        ]);
+
+        # localtunnel via npm
+        localtunnel = pkgs.buildNpmPackage {
+          pname = "localtunnel";
+          version = "2.0.2";
+          src = pkgs.fetchFromGitHub {
+            owner = "localtunnel";
+            repo = "localtunnel";
+            rev = "v2.0.2";
+            hash = "sha256-deKDwCjGT+0YjeW/AM2J6IH+hEoQrESmKKM23n0JLWY=";
+          };
+          npmDepsHash = "sha256-R9FYkEe93oGF+dR7i1MxwzEW3EM3SasH/B6LLC2CNXM=";
+          dontNpmBuild = true;
+        };
+
+        runtimePath = pkgs.lib.makeBinPath [
+          pythonEnv
+          localtunnel
+        ];
+
+      in {
+        packages.default = pkgs.stdenv.mkDerivation {
+          pname = "telegram-fitness-bot";
+          version = "0.1.0";
+
+          src = pkgs.lib.cleanSource ./.;
+
+          nativeBuildInputs = [ pkgs.makeWrapper ];
+
+          installPhase = ''
+            mkdir -p $out/lib/telegram-fitness-bot
+            cp -r start.py bot.py server.py database.py config.py webapp $out/lib/telegram-fitness-bot/
+
+            mkdir -p $out/bin
+
+            # Main entry point: `nix run` → start.py
+            makeWrapper ${pythonEnv}/bin/python $out/bin/telegram-fitness-bot \
+              --prefix PATH : ${runtimePath} \
+              --add-flags "$out/lib/telegram-fitness-bot/start.py"
+          '';
+
+          meta = with pkgs.lib; {
+            description = "Telegram Mini App for tracking gym workouts";
+            license = licenses.mit;
+            mainProgram = "telegram-fitness-bot";
+          };
+        };
+
+        # `nix develop` — interactive dev shell
+        devShells.default = pkgs.mkShell {
+          packages = [
+            pythonEnv
+            localtunnel
+          ];
+
+          shellHook = ''
+            echo ""
+            echo "  Fitness Bot dev shell"
+            echo "  python: $(python --version)"
+            echo "  lt:     $(lt --version)"
+            echo ""
+            echo "  Run:  python start.py"
+            echo ""
+          '';
+        };
+      }
+    );
+}