fix(02-04): pin cargo-chef to bookworm, fix axum 0.8 path syntax

[Rule 1 - Bug] Dockerfile: cargo-chef:latest-rust-1 uses Debian trixie (glibc 2.41)
but runtime image debian:bookworm-slim uses glibc 2.36 -- binary fails to start.
Fix: use lukemathwalker/cargo-chef:latest-rust-1-bookworm (glibc 2.36).

[Rule 1 - Bug] routes/mod.rs: axum 0.8 requires {param} path syntax, not :param.
The :height route panicked at runtime (cargo check passes but axum validates
at Router construction time, not compile time).

Author: andrewklau

apps/block-proxy/Dockerfile

@@ -1,5 +1,8 @@
 # Stage 1: Chef planner — compute dependency recipe
-FROM lukemathwalker/cargo-chef:latest-rust-1 AS chef
+# Use the bookworm-pinned image so builder and runtime both use glibc 2.36.
+# The untagged latest-rust-1 uses Debian trixie (glibc 2.41) which is incompatible
+# with the debian:bookworm-slim runtime image (glibc 2.36).
+FROM lukemathwalker/cargo-chef:latest-rust-1-bookworm AS chef
 WORKDIR /app
 
 FROM chef AS planner

apps/block-proxy/src/routes/mod.rs

@@ -25,7 +25,7 @@ pub fn build_router(state: AppState) -> Router {
     Router::new()
         .route("/healthz", get(health_handler))
         .route("/readyz", get(readyz_handler))
-        .route("/v0/block/:height", get(block_handler))
+        .route("/v0/block/{height}", get(block_handler))
         .route("/v0/last_block/final", get(last_block_final_handler))
         .layer(
             ServiceBuilder::new()