Update Dockerfile to use debian:unstable-slim

.devcontainer/Dockerfile

@@ -1,26 +1,52 @@
 # ------------------------------------------------------------
 # Base Image
 # ------------------------------------------------------------
-FROM mcr.microsoft.com/devcontainers/base:debian
+FROM debian:unstable-slim
+
+ENV DEBIAN_FRONTEND=noninteractive
+ENV LANG=C.UTF-8
+ENV LC_ALL=C.UTF-8
 
 # ------------------------------------------------------------
 # System Dependencies
 # ------------------------------------------------------------
-RUN apt update && apt upgrade -y && \
+RUN apt-get update && apt-get upgrade -y && \
     apt-get install -y --no-install-recommends \
+        curl \
+        ca-certificates \
         git \
-        git-lfs \
+        build-essential \
+        sudo \
         fish \
+        unzip \
+        xz-utils \
+        libatomic1 \
+        libc6 \
+        wget \
         nodejs \
-        npm \
+        npm && \
-        curl
+    rm -rf /var/lib/apt/lists/*
+
+# ------------------------------------------------------------
+# Create Non-Root User
+# ------------------------------------------------------------
+ARG USERNAME=devuser
+ARG UID=1000
+ARG GID=1000
+
+RUN groupadd --gid ${GID} ${USERNAME} && \
+    useradd --uid ${UID} --gid ${GID} -m -s /usr/bin/fish ${USERNAME} && \
+    echo "${USERNAME} ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers
+
+USER ${USERNAME}
+WORKDIR /home/${USERNAME}
 
 # ------------------------------------------------------------
 # Install Bun (Non-Root)
 # ------------------------------------------------------------
-ENV BUN_INSTALL="$HOME/.bun"
+ENV BUN_INSTALL=/home/${USERNAME}/.bun
-ENV PATH="$BUN_INSTALL/bin:$PATH"
+ENV PATH="${BUN_INSTALL}/bin:${PATH}"
-    
+
 RUN curl -fsSL https://bun.sh/install | bash
 
 # ------------------------------------------------------------
@@ -32,11 +58,11 @@ RUN curl -fsSL https://opencode.ai/install -o opencode-install && \
     rm opencode-install
 
 # Add OpenCode to PATH permanently
-ENV PATH="$HOME/.opencode/bin:$PATH"
+ENV PATH="/home/${USERNAME}/.opencode/bin:${PATH}"
     
 # ------------------------------------------------------------
 # Ensure fish is Default Shell
 # ------------------------------------------------------------
 ENV SHELL=/usr/bin/fish
 
-CMD ["fish"]
+CMD ["fish"]