Refactor code structure for improved readability and maintainability

app.py

@@ -16,7 +16,7 @@ import urllib.request as _urlreq
 import urllib.error   as _urlerr
 from datetime import datetime
 from pathlib import Path
-from flask import Flask, jsonify, request
+from flask import Flask, jsonify, request, send_file
 
 app = Flask(__name__)
 
@@ -1506,6 +1506,13 @@ def run_uploads(local_dir: Path, cfg: dict, upload_files=None):
 def index():
     return HTML.replace('__PICOPY_VERSION__', VERSION)
 
+@app.route('/logo.png')
+def r_logo():
+    logo = Path(__file__).with_name('PiCopy_Logo.png')
+    if logo.exists():
+        return send_file(logo, mimetype='image/png')
+    return '', 404
+
 @app.route('/api/devices')
 def r_devices():
     return jsonify(usb_devices())
@@ -2084,7 +2091,7 @@ body{background:var(--bg);color:var(--txt);font-family:-apple-system,BlinkMacSys
 /* -- Topbar -- */
 .topbar{background:var(--bg2);border-bottom:1px solid var(--brd);padding:.75rem 1.5rem;display:flex;align-items:center;gap:1rem;position:sticky;top:0;z-index:100;backdrop-filter:blur(8px)}
 .logo{display:flex;align-items:center;gap:.55rem;font-size:1rem;font-weight:700;letter-spacing:-.02em;color:var(--txt)}
-.logo-dot{width:8px;height:8px;border-radius:50%;background:var(--acc);box-shadow:0 0 8px var(--acc)}
+.logo-img{height:28px;width:auto;object-fit:contain}
 .topbar-wifi{margin-left:auto;display:flex;align-items:center;gap:.6rem;font-size:.82rem;background:var(--surf);border:1px solid var(--brd);border-radius:9999px;padding:.3rem .75rem}
 .topbar-wifi~.topbar-wifi,.wdot{width:7px;height:7px;border-radius:50%;transition:.3s;flex-shrink:0}
 .wdot.c{background:var(--grn);box-shadow:0 0 6px var(--grn)}
@@ -2273,7 +2280,7 @@ body{background:var(--bg);color:var(--txt);font-family:-apple-system,BlinkMacSys
 <!-- Topbar -->
 <header class="topbar">
   <div class="logo">
-    <div class="logo-dot"></div>
+    <img src="/logo.png" alt="PiCopy" class="logo-img">
     PiCopy
   </div>
   <div id="upd-badge" class="upd-badge" onclick="installUpdate()" title="Klicken zum Installieren">