refactor deployment config and exchange integrations

Simplify runtime configuration and remove legacy database and settings surface so new installs are easier to operate.
Refresh deployment assets, docs, and order execution behavior to keep the packaged app aligned with the current backend.

Made-with: Cursor

backend_api_python/run.py

@@ -47,14 +47,6 @@ def _apply_proxy_env():
     # If user provided explicit proxy URL, honor it.
     proxy_url = (os.getenv('PROXY_URL') or '').strip()
 
-    # If user only provided port, build a URL (common local proxy setups).
-    if not proxy_url:
-        port = (os.getenv('PROXY_PORT') or '').strip()
-        if port:
-            host = (os.getenv('PROXY_HOST') or '127.0.0.1').strip()
-            scheme = (os.getenv('PROXY_SCHEME') or 'socks5h').strip()
-            proxy_url = f"{scheme}://{host}:{port}"
-
     if not proxy_url:
         return
 
@@ -63,9 +55,6 @@ def _apply_proxy_env():
     _set_if_blank('HTTP_PROXY', proxy_url)
     _set_if_blank('HTTPS_PROXY', proxy_url)
 
-    # CCXT config uses CCXT_PROXY in our codebase.
-    _set_if_blank('CCXT_PROXY', proxy_url)
-
 _apply_proxy_env()
 
 # Add project root to Python path