Raise HTTP WriteTimeout above the request middleware timeout (closes #62) (#72)

Raise `httpWriteTimeout` in `internal/server/http.go` from 10s to `65 * time.Second` so it comfortably exceeds the router's 60s `requestTimeout`. This makes the `middleware.Timeout(60s)` the effective request limit — a slow response now returns a clean 503 from the middleware instead of being cut at the socket write deadline by the transport.

`httpReadTimeout` stays at 10s. A comment on `httpWriteTimeout` documents that it must remain above the 60s request timeout. Change is confined to `internal/server/http.go`; `routes.go` is untouched.

Closes #62

Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #72
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

internal/server/http.go

@@ -13,8 +13,11 @@ const (
 	httpReadTimeout = 10 * time.Second
 
 	// httpWriteTimeout is the maximum duration before timing out
-	// writes of the response.
-	httpWriteTimeout = 10 * time.Second
+	// writes of the response. It must stay above the router's
+	// requestTimeout (60s, in routes.go) so the middleware timeout
+	// fires first and returns a clean 503, rather than the transport
+	// cutting the connection at the socket write deadline.
+	httpWriteTimeout = 65 * time.Second
 
 	// httpMaxHeaderBytes is the maximum number of bytes the
 	// server will read parsing the request headers.