fix(docker): track stable Rust in the builder stage (#72)

The pinned rust:1.83 predates edition2024 dependencies (clap_derive 4.6
fails to parse), breaking the image publish workflow. Track rust:1-bookworm
(latest stable), matching CI's dtolnay/rust-toolchain@stable.

Signed-off-by: Val Alexander <bunsthedev@gmail.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: BunsDev

Dockerfile

@@ -11,7 +11,7 @@
 # ready-to-edit Compose service.
 
 # ── Builder ─────────────────────────────────────────────────────────────────
-FROM rust:1.83-bookworm AS builder
+FROM rust:1-bookworm AS builder
 WORKDIR /app
 
 # Copy the whole workspace and build the release binary. (A cold build pulls the