add SNI-rewrite MITM tunnels for YouTube/googlevideo + fix gzip decode

SNI-rewrite tunnels (src/proxy_server.rs):
- CONNECT to youtube.com / googlevideo.com / doubleclick / etc. now bypasses
  the Apps Script relay entirely and goes direct to the Google edge IP
  with SNI=front_domain.
- Accepts browser TLS with our MITM cert, opens outbound TLS to
  config.google_ip with SNI=config.front_domain, bridges decrypted bytes.
- Matches Python's _do_sni_rewrite_tunnel behavior. Faster than relay for
  large streams (video).
- Also respects config.hosts override map (custom IP per suffix).

gzip decode fix (src/domain_fronter.rs):
- Apps Script outer response is gzipped. Previous stub always failed,
  causing 'non-utf8 json' errors. Swapped in flate2::GzDecoder.
- Verified end-to-end: HTTP and HTTPS requests through apps_script
  relay succeed and return real Google IPs.

Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "adler2"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.4"
@@ -123,6 +129,15 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "crc32fast"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9481c1c90cbf2ac953f07c8d4a58aa3945c425b7185c9154d67a65e4230da511"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.10.0"
@@ -191,6 +206,16 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 
+[[package]]
+name = "flate2"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843fba2746e448b37e26a819579957415c8cef339bf08564fe8b7ddbd959573c"
+dependencies = [
+ "crc32fast",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -344,6 +369,7 @@ version = "0.1.0"
 dependencies = [
  "base64",
  "bytes",
+ "flate2",
  "h2",
  "http",
  "httparse",
@@ -369,6 +395,16 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
 
+[[package]]
+name = "miniz_oxide"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
+dependencies = [
+ "adler2",
+ "simd-adler32",
+]
+
 [[package]]
 name = "mio"
 version = "1.2.0"
@@ -701,6 +737,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
+
 [[package]]
 name = "slab"
 version = "0.4.12"