Add native MTProxy support

[makarovstas]

Summary

Adds first-class MTProxy support directly into the transport layer. Users can now connect through an MTProxy server by passing
scheme: "mtproxy" in the proxy dict — the same way SOCKS5 proxies are configured.

All three secret formats are supported:

Prefix	Protocol
ee<32 hex><domain hex>	Fake-TLS with SNI domain
dd<32 hex>	Fake-TLS without fixed SNI
<32 hex>	Plain obfuscation (obf2)

Usage

from pyrogram import Client

client = Client(
    "session",
    api_id=...,
    api_hash=...,
    proxy={
        "scheme": "mtproxy",
        "hostname": "your.mtproxy.host",
        "port": 443,
        "secret": "eeeab756314c868a251adde878bdf93b7473746f726167652e79616e646578636c6f75642e6e6574",
    },
)

The secret is the standard MTProxy secret string from the proxy's connection link (tg://proxy?...).

Implementation details

• TCP — new _connect_via_mtproxy, _connect_via_mtproxy_obf2, _connect_via_mtproxy_faketls methods handle the handshake; send/recv transparently encrypt/decrypt traffic using AES-CTR once the connection is established

• TCPAbridged — skips the abridged \xef marker byte for MTProxy connections (the protocol tag is embedded in the obfuscation nonce instead)

• Connection — injects dc_id into the proxy dict before passing it to the transport so the nonce can encode the target DC

• ProxyDict — added optional secret field

Fake-TLS implementation follows the mtprotoproxy spec: HMAC-SHA256 signed ClientHello padded to ≥ 512 bytes, padded-intermediate framing (0xdd × 4) after the TLS handshake.

[makarovstas]

@KurimuzonAkuma hi bratello 🙂

[KurimuzonAkuma]

@makarovstas Да там вайбкод нейрослоп от клода, я еще не тестил, боюсь.....