[feat](trx-server): gzip-compress history replay blob

Add flate2 dependency and a new AUDIO_MSG_HISTORY_COMPRESSED (0x0a)
wire type. The server gzip-compresses the full history blob before
sending; JSON history compresses ~10-20x so both transfer size and
client wait time drop significantly. The client decompresses and
dispatches sub-messages from the embedded framed stream. MAX_PAYLOAD_SIZE
is kept at 1 MB for normal messages; a separate 16 MB limit is applied
only to the compressed history type.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/Cargo.toml

@@ -8,6 +8,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+flate2 = { workspace = true }
 tokio = { workspace = true, features = ["full"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
@@ -27,4 +28,4 @@ trx-frontend-http-json = { path = "trx-frontend/trx-frontend-http-json" }
 trx-frontend-rigctl = { path = "trx-frontend/trx-frontend-rigctl" }
 
 [features]
-default = []
+default = []