[code][fix] improvements for LAN 202503

- more robust client <-> server connection
  - new client event: DownloadGameFilesFailed
  - 3 seconds to reconnect
  - retry forever if server is gone and never lose a UI request

- code cleanup here and there (mostly server)

crates/lanspread-proto/src/lib.rs

@@ -1,7 +1,6 @@
 use bytes::Bytes;
 use lanspread_db::db::{Game, GameFileDescription};
 use serde::{Deserialize, Serialize};
-use tracing::error;
 
 #[derive(Debug, Serialize, Deserialize)]
 pub enum Request {
@@ -15,8 +14,11 @@ pub enum Request {
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub enum Response {
     Pong,
-    Games(Vec<Game>),
-    GetGame(Vec<GameFileDescription>),
+    ListGames(Vec<Game>),
+    GetGame {
+        id: String,
+        file_descriptions: Vec<GameFileDescription>,
+    },
     GameNotFound(String),
     InvalidRequest(Bytes, String),
     EncodingError(String),
@@ -35,11 +37,7 @@ impl Message for Request {
         match serde_json::from_slice(&bytes) {
             Ok(t) => t,
             Err(e) => {
-                tracing::error!(
-                    "got invalid request from client (error: {}): {}",
-                    e,
-                    String::from_utf8_lossy(&bytes)
-                );
+                tracing::error!(?e, "Request decoding error");
                 Request::Invalid(bytes, e.to_string())
             }
         }
@@ -49,7 +47,7 @@ impl Message for Request {
         match serde_json::to_vec(self) {
             Ok(s) => Bytes::from(s),
             Err(e) => {
-                error!(?e, "Request encoding error");
+                tracing::error!(?e, "Request encoding error");
                 Bytes::from(format!(r#"{{"error": "encoding error: {e}"}}"#))
             }
         }
@@ -61,7 +59,10 @@ impl Message for Response {
     fn decode(bytes: Bytes) -> Self {
         match serde_json::from_slice(&bytes) {
             Ok(t) => t,
-            Err(e) => Response::DecodingError(bytes, e.to_string()),
+            Err(e) => {
+                tracing::error!(?e, "Response decoding error");
+                Response::DecodingError(bytes, e.to_string())
+            }
         }
     }
 
@@ -69,7 +70,7 @@ impl Message for Response {
         match serde_json::to_vec(self) {
             Ok(s) => Bytes::from(s),
             Err(e) => {
-                error!(?e, "Response encoding error");
+                tracing::error!(?e, "Response encoding error");
                 Bytes::from(format!(r#"{{"error": "encoding error: {e}"}}"#))
             }
         }