[fix](trx-frontend-http): send decode history on connect

Co-authored-by: Codex <codex@openai.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

src/trx-client/trx-frontend/trx-frontend-http/src/api.rs

@@ -103,6 +103,27 @@ pub async fn decode_events() -> Result<HttpResponse, Error> {
     };
     tracing::info!("/decode SSE client connected");
 
+    let history = {
+        let mut out = Vec::new();
+        out.extend(
+            crate::server::audio::snapshot_aprs_history()
+                .into_iter()
+                .map(trx_core::decode::DecodedMessage::Aprs),
+        );
+        out.extend(
+            crate::server::audio::snapshot_ft8_history()
+                .into_iter()
+                .map(trx_core::decode::DecodedMessage::Ft8),
+        );
+        out
+    };
+
+    let history_stream = futures_util::stream::iter(history.into_iter().filter_map(|msg| {
+        serde_json::to_string(&msg)
+            .ok()
+            .map(|json| Ok::<Bytes, Error>(Bytes::from(format!("data: {json}\n\n"))))
+    }));
+
     let decode_stream = futures_util::stream::unfold(decode_rx, |mut rx| async move {
         loop {
             match rx.recv().await {
@@ -123,7 +144,7 @@ pub async fn decode_events() -> Result<HttpResponse, Error> {
     let pings = IntervalStream::new(time::interval(Duration::from_secs(15)))
         .map(|_| Ok::<Bytes, Error>(Bytes::from(": ping\n\n")));
 
-    let stream = select(pings, decode_stream);
+    let stream = history_stream.chain(select(pings, decode_stream));
 
     Ok(HttpResponse::Ok()
         .insert_header((header::CONTENT_TYPE, "text/event-stream"))