feat(frontend): Tauri Apps, Shared UI Library und Nix Flake

- packages/ui: Shared React Component Library (Button, Card, Badge, Input)
  mit Tailwind v4 @theme Design Tokens (oklch)
- apps/web: ERP Web-UI (Vite + React + Tailwind v4, API-Proxy :8080)
- apps/scanner: Tauri v2 Mobile App mit Barcode-Scanner Plugin
  (cfg(mobile) für Desktop-Kompatibilität)
- flake.nix: Nix Flake mit rust-overlay, Tauri System-Deps (GTK,
  WebKitGTK, libsoup, OpenSSL), ersetzt shell.nix
- justfile: Dev-Befehle für alle Projekte (backend, cli, web, scanner)
- frontend/CLAUDE.md: Agent Guide mit Base UI Docs Referenz

frontend/apps/scanner/src-tauri/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "effigenix-scanner"
+version = "0.1.0"
+description = "Effigenix mobile scanner app"
+edition = "2021"
+
+[lib]
+name = "effigenix_scanner_lib"
+crate-type = ["lib", "cdylib", "staticlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2", features = [] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+
+[target.'cfg(any(target_os = "android", target_os = "ios"))'.dependencies]
+tauri-plugin-barcode-scanner = "2"

frontend/apps/scanner/src-tauri/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    tauri_build::build()
+}

frontend/apps/scanner/src-tauri/capabilities/default.json

@@ -0,0 +1,8 @@
+{
+  "identifier": "default",
+  "description": "Default capabilities for the scanner app",
+  "windows": ["main"],
+  "permissions": [
+    "core:default"
+  ]
+}

frontend/apps/scanner/src-tauri/gen/schemas/capabilities.json

@@ -0,0 +1 @@
+{"default":{"identifier":"default","description":"Default capabilities for the scanner app","local":true,"windows":["main"],"permissions":["core:default"]}}

frontend/apps/scanner/src-tauri/icons/android/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+  <background android:drawable="@color/ic_launcher_background"/>
+</adaptive-icon>

frontend/apps/scanner/src-tauri/icons/android/values/ic_launcher_background.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="ic_launcher_background">#fff</color>
+</resources>

frontend/apps/scanner/src-tauri/src/lib.rs

@@ -0,0 +1,11 @@
+#[cfg_attr(mobile, tauri::mobile_entry_point)]
+pub fn run() {
+    let builder = tauri::Builder::default();
+
+    #[cfg(mobile)]
+    let builder = builder.plugin(tauri_plugin_barcode_scanner::init());
+
+    builder
+        .run(tauri::generate_context!())
+        .expect("error while running tauri application");
+}

frontend/apps/scanner/src-tauri/src/main.rs

@@ -0,0 +1,5 @@
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+fn main() {
+    effigenix_scanner_lib::run()
+}

frontend/apps/scanner/src-tauri/tauri.conf.json

@@ -0,0 +1,37 @@
+{
+  "$schema": "https://raw.githubusercontent.com/nicfit/tauri/tauri-v2/crates/tauri-cli/schema.json",
+  "productName": "Effigenix Scanner",
+  "version": "0.1.0",
+  "identifier": "de.effigenix.scanner",
+  "build": {
+    "frontendDist": "../dist",
+    "devUrl": "http://localhost:1420",
+    "beforeDevCommand": "pnpm dev",
+    "beforeBuildCommand": "pnpm build"
+  },
+  "app": {
+    "withGlobalTauri": false,
+    "windows": [
+      {
+        "title": "Effigenix Scanner",
+        "width": 400,
+        "height": 700,
+        "resizable": true
+      }
+    ],
+    "security": {
+      "csp": null
+    }
+  },
+  "bundle": {
+    "active": true,
+    "targets": "all",
+    "icon": [
+      "icons/32x32.png",
+      "icons/128x128.png",
+      "icons/128x128@2x.png",
+      "icons/icon.icns",
+      "icons/icon.ico"
+    ]
+  }
+}