version updates

backend/main.py

@@ -12,6 +12,7 @@ from curl_cffi import requests as impersonate_requests
 import threading
 import io
 import time
+import hashlib
 from urllib.parse import urljoin
 
 # Browser to impersonate at the TLS/HTTP layer. Some origins (e.g. the
@@ -355,6 +356,63 @@ def index():
 def favicon():
     return send_from_directory(app.static_folder, 'favicon.ico')
 
+# --- Frontend asset version tracking -------------------------------------
+# The client polls /api/version and, when a tracked file's content hash
+# changes, hot-swaps CSS in place or reloads the page. This lets a deploy
+# reach already-open tabs without a manual refresh.
+_FRONTEND_DIR = os.path.abspath(app.static_folder)
+_VERSION_EXTS = ('.html', '.css', '.js')
+_version_cache = {'mtime': None, 'payload': None}
+_version_lock = threading.Lock()
+
+
+def _scan_frontend_files():
+    """Map served relative paths -> absolute paths for tracked frontend files."""
+    files = {}
+    for root, _dirs, names in os.walk(_FRONTEND_DIR):
+        for name in names:
+            if os.path.splitext(name)[1].lower() not in _VERSION_EXTS:
+                continue
+            path = os.path.join(root, name)
+            rel = os.path.relpath(path, _FRONTEND_DIR).replace(os.sep, '/')
+            files[rel] = path
+    return files
+
+
+def _compute_version_payload(files):
+    """Hash each tracked file's contents plus a combined version fingerprint."""
+    file_hashes = {}
+    combined = hashlib.md5()
+    for rel in sorted(files):
+        try:
+            with open(files[rel], 'rb') as fh:
+                digest = hashlib.md5(fh.read()).hexdigest()
+        except OSError:
+            continue
+        file_hashes[rel] = digest
+        combined.update(rel.encode('utf-8'))
+        combined.update(digest.encode('utf-8'))
+    return {'version': combined.hexdigest(), 'files': file_hashes}
+
+
+@app.route('/api/version', methods=['GET'])
+def frontend_version():
+    files = _scan_frontend_files()
+    # Use the newest mtime across tracked files as a cheap cache key so frequent
+    # polls only re-hash contents when something on disk actually changed.
+    try:
+        latest_mtime = max((os.path.getmtime(p) for p in files.values()), default=0)
+    except OSError:
+        latest_mtime = 0
+    with _version_lock:
+        if _version_cache['mtime'] != latest_mtime or _version_cache['payload'] is None:
+            _version_cache['payload'] = _compute_version_payload(files)
+            _version_cache['mtime'] = latest_mtime
+        payload = _version_cache['payload']
+    resp = jsonify(payload)
+    resp.headers['Cache-Control'] = 'no-store'
+    return resp
+
 @app.route('/api/stream', methods=['POST', 'GET', 'HEAD'])
 def stream_video():
     # Note: <video> tags perform GET. To support your POST requirement,