Add app source and tests

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

lib/Peach/about/external/data/EnvCheck.dart

@@ -0,0 +1,151 @@
+import 'package:flutter/material.dart';
+
+/// A tool/runtime PeachDeployments can detect on a server and install if
+/// missing. [detect] prints a version line to stdout when present, nothing
+/// otherwise (guarded by `command -v`). [pkg] maps a package manager to the
+/// package(s) to install. [unit] is a systemd unit to `enable --now` after.
+class EnvTool {
+  final String key;
+  final String label;
+  final IconData icon;
+  final String detect;
+  final Map<String, String> pkg;
+  final String? unit;
+
+  const EnvTool(
+    this.key,
+    this.label,
+    this.icon,
+    this.detect,
+    this.pkg, {
+    this.unit,
+  });
+
+  String packagesFor(String pm) => pkg[pm] ?? key;
+}
+
+const List<EnvTool> kEnvTools = [
+  EnvTool(
+    'java',
+    'Java (JDK)',
+    Icons.coffee,
+    'command -v java >/dev/null 2>&1 && java -version 2>&1 | head -n1',
+    {
+      'apt': 'openjdk-17-jdk',
+      'dnf': 'java-17-openjdk-devel',
+      'yum': 'java-17-openjdk-devel',
+      'apk': 'openjdk17',
+      'zypper': 'java-17-openjdk-devel',
+      'pacman': 'jdk-openjdk',
+    },
+  ),
+  EnvTool(
+    'mariadb',
+    'MariaDB / MySQL',
+    Icons.storage,
+    '(command -v mariadb >/dev/null 2>&1 && mariadb --version 2>&1 | head -n1) || '
+        '(command -v mysql >/dev/null 2>&1 && mysql --version 2>&1 | head -n1)',
+    {
+      'apt': 'mariadb-server',
+      'dnf': 'mariadb-server',
+      'yum': 'mariadb-server',
+      'apk': 'mariadb mariadb-client',
+      'zypper': 'mariadb',
+      'pacman': 'mariadb',
+    },
+    unit: 'mariadb',
+  ),
+  EnvTool(
+    'postgres',
+    'PostgreSQL',
+    Icons.dataset,
+    'command -v psql >/dev/null 2>&1 && psql --version 2>&1 | head -n1',
+    {
+      'apt': 'postgresql',
+      'dnf': 'postgresql-server',
+      'yum': 'postgresql-server',
+      'apk': 'postgresql',
+      'zypper': 'postgresql-server',
+      'pacman': 'postgresql',
+    },
+    unit: 'postgresql',
+  ),
+  EnvTool(
+    'nginx',
+    'nginx',
+    Icons.dns,
+    'command -v nginx >/dev/null 2>&1 && nginx -v 2>&1 | head -n1',
+    {
+      'apt': 'nginx',
+      'dnf': 'nginx',
+      'yum': 'nginx',
+      'apk': 'nginx',
+      'zypper': 'nginx',
+      'pacman': 'nginx',
+    },
+    unit: 'nginx',
+  ),
+  EnvTool(
+    'docker',
+    'Docker',
+    Icons.inventory_2,
+    'command -v docker >/dev/null 2>&1 && docker --version 2>&1 | head -n1',
+    {
+      'apt': 'docker.io',
+      'dnf': 'docker',
+      'yum': 'docker',
+      'apk': 'docker',
+      'zypper': 'docker',
+      'pacman': 'docker',
+    },
+    unit: 'docker',
+  ),
+  EnvTool(
+    'node',
+    'Node.js',
+    Icons.javascript,
+    'command -v node >/dev/null 2>&1 && node --version 2>&1 | head -n1',
+    {
+      'apt': 'nodejs npm',
+      'dnf': 'nodejs',
+      'yum': 'nodejs',
+      'apk': 'nodejs npm',
+      'zypper': 'nodejs',
+      'pacman': 'nodejs npm',
+    },
+  ),
+  EnvTool(
+    'git',
+    'Git',
+    Icons.merge_type,
+    'command -v git >/dev/null 2>&1 && git --version 2>&1 | head -n1',
+    {
+      'apt': 'git',
+      'dnf': 'git',
+      'yum': 'git',
+      'apk': 'git',
+      'zypper': 'git',
+      'pacman': 'git',
+    },
+  ),
+];
+
+/// Builds the install command for a detected package manager.
+String installCommandFor(String pm, String packages) {
+  switch (pm) {
+    case 'apt':
+      return 'apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y $packages';
+    case 'dnf':
+      return 'dnf install -y $packages';
+    case 'yum':
+      return 'yum install -y $packages';
+    case 'apk':
+      return 'apk add --no-cache $packages';
+    case 'zypper':
+      return 'zypper --non-interactive install $packages';
+    case 'pacman':
+      return 'pacman -Sy --noconfirm $packages';
+    default:
+      return 'echo "Unsupported package manager"; false';
+  }
+}