Add a docker build step.

backend/Cargo.lock

@@ -289,6 +289,7 @@ dependencies = [
  "serde",
  "sqlx",
  "tokio",
+ "tower-http",
  "tracing",
  "tracing-subscriber",
  "uuid",
@@ -3490,6 +3491,20 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "tower-http"
+version = "0.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "adc82fd73de2a9722ac5da747f12383d2bfdb93591ee6c58486e0097890f05f2"
+dependencies = [
+ "bitflags 2.9.3",
+ "bytes",
+ "http 1.3.1",
+ "pin-project-lite",
+ "tower-layer",
+ "tower-service",
+]
+
 [[package]]
 name = "tower-layer"
 version = "0.3.3"