feat: Add perl for OpenSSL builds

- Add perl to Dockerfile for rfs OpenSSL compilation
- Clean up rustup environment (remove gcc complications)
- Ready for complete build debugging

Dockerfile

@@ -1,11 +1,10 @@
 # Zero OS Alpine Initramfs Builder Container
 FROM alpine:3.22
 
-# Install build dependencies including proper musl toolchain
+# Install build dependencies including rustup
 RUN apk add --no-cache \
     build-base \
-    rust \
-    cargo \
+    rustup \
     upx \
     git \
     wget \
@@ -19,17 +18,19 @@ RUN apk add --no-cache \
     musl-utils \
     pkgconfig \
     openssl-dev \
+    perl \
     bash \
     findutils \
     grep \
     sed \
     coreutils
 
-# Create musl-gcc wrapper (Alpine's gcc already targets musl)
-RUN echo '#!/bin/sh' > /usr/bin/musl-gcc && \
-    echo 'exec gcc -static "$@"' >> /usr/bin/musl-gcc && \
-    chmod +x /usr/bin/musl-gcc && \
-    which musl-gcc
+# Setup rustup with stable and musl target
+RUN rustup-init -y && \
+    source /root/.cargo/env && \
+    rustup install stable && \
+    rustup target add x86_64-unknown-linux-musl && \
+    echo 'source /root/.cargo/env' >> /etc/profile
 
 # Create non-root user for builds matching host user
 RUN adduser -D -s /bin/bash builder
@@ -38,12 +39,8 @@ RUN adduser -D -s /bin/bash builder
 WORKDIR /workspace
 RUN chown builder:builder /workspace
 
-# Set environment variables for musl static linking with Alpine's Rust
-ENV RUSTFLAGS="-C target-feature=+crt-static -C linker=musl-gcc"
-ENV CC="musl-gcc"
-ENV TARGET_CC="musl-gcc"
-ENV CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER="musl-gcc"
-
-# Don't switch to builder user yet - let the runtime handle it
+# Set environment variables - rustup handles everything
+ENV PATH="/root/.cargo/bin:${PATH}"
+ENV RUSTFLAGS="-C target-feature=+crt-static"
 
 CMD ["/bin/bash"]