feat(config): add mtproto proxy support

Introduce optional MTProto proxy configuration sourced from environment variables, expose related settings in `config.py`, document the variables in `dockercompose.yml`, and pass the proxy configuration to the Telegram client initialization.

config.py

@@ -47,6 +47,17 @@ def get_settings() -> dict[str, Any]:
 
     log_level = os.getenv("LOG_LEVEL", "INFO")
 
+    # Build MTProto proxy config if proxy host is provided
+    proxy_host = os.getenv("TG_PROXY_HOST")
+    proxy: dict[str, Any] | None = None
+    if proxy_host:
+        proxy = {
+            "scheme": "mtproto",
+            "hostname": proxy_host,
+            "port": int(os.getenv("TG_PROXY_PORT") or 443),
+            "secret": os.getenv("TG_PROXY_SECRET", ""),
+        }
+
     return {
         "tg_api_id": int(tg_api_id),
         "tg_api_hash": tg_api_hash,
@@ -60,4 +71,5 @@ def get_settings() -> dict[str, Any]:
         "time_based_merge": os.getenv("TIME_BASED_MERGE", "False").strip() in ["True", "true"],
         "show_bridge_link": os.getenv("SHOW_BRIDGE_LINK", "False").strip() in ["True", "true"],
         "show_post_flags": os.getenv("SHOW_POST_FLAGS", "False").strip() in ["True", "true"],
-    } 
+        "proxy": proxy,
+    }

dockercompose.yml

@@ -8,6 +8,9 @@ services:
     environment:
       TG_API_ID: XXX
       TG_API_HASH: XXX
+      # TG_PROXY_HOST: 127.0.0.1     # MTProto proxy host (optional)
+      # TG_PROXY_PORT: 443            # MTProto proxy port (default: 443)
+      # TG_PROXY_SECRET: XXX          # MTProto proxy secret
       PYROGRAM_BRIDGE_URL: https://pgbridge.example.com
       API_PORT: 80
       TOKEN: ХХХ

telegram_client.py

@@ -32,6 +32,7 @@ class TelegramClient:
             api_id=settings["tg_api_id"],
             api_hash=settings["tg_api_hash"],
             workdir=settings["session_path"],
+            proxy=settings["proxy"],  # MTProto proxy config, None if not set
         )
         self.disconnect_count = 0
         self.max_disconnects = 3