Fix Dockerfile: Use multi-stage build for OpenCode

- Added builder stage with all build dependencies
- Isolated build process to prevent failures in final stage
- Retry mechanism for bun install
- Copy only built binary to final image

Dockerfile

@@ -1,11 +1,56 @@
 # Web-based PowerShell + SST OpenCode terminal
 # Builds OpenCode CLI from source during Docker build
+FROM ubuntu:24.04 AS opencode-builder
+
+ARG BUN_VERSION=1.3.8
+
+ENV DEBIAN_FRONTEND=noninteractive \
+    LANG=C.UTF-8 \
+    LC_ALL=C.UTF-8
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        ca-certificates \
+        curl \
+        git \
+        tar \
+        xz-utils \
+        gzip \
+        unzip \
+        build-essential \
+        python3 \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Node.js (required for some dependencies)
+RUN curl -fsSL -o /tmp/node.tar.xz \
+    "https://nodejs.org/dist/v20.18.1/node-v20.18.1-linux-x64.tar.xz" \
+    && tar -xJf /tmp/node.tar.xz -C /usr/local --strip-components=1 \
+    && rm -f /tmp/node.tar.xz
+
+# Install Bun
+RUN npm install -g bun@${BUN_VERSION} \
+    && bun --version
+
+# Copy OpenCode source
+COPY opencode /opt/opencode-src
+WORKDIR /opt/opencode-src
+
+# Configure git for any workspace dependencies that use git URLs
+RUN git config --global url."https://github.com/".insteadOf "ssh://git@github.com/"
+
+# Install dependencies at root level first (for workspaces)
+ENV HUSKY=0
+RUN bun install 2>&1 || (echo "Retrying bun install..." && bun install --force 2>&1)
+
+# Build OpenCode CLI
+RUN cd packages/opencode && bun run ./script/build.ts --single 2>&1
+
+# Final stage
 FROM ubuntu:24.04
 
 ARG PWSH_VERSION=7.4.6
 ARG NODE_VERSION=20.18.1
 ARG TTYD_VERSION=1.7.7
-ARG BUN_VERSION=1.3.8
 
 ENV DEBIAN_FRONTEND=noninteractive \
     TERM=xterm-256color \
@@ -24,7 +69,6 @@ RUN apt-get update \
         tini \
         libicu-dev \
         libssl-dev \
-        unzip \
     && rm -rf /var/lib/apt/lists/*
 
 # Install Node.js
@@ -35,10 +79,6 @@ RUN curl -fsSL -o /tmp/node.tar.xz \
     && ln -sf /usr/local/bin/npm /usr/bin/npm \
     && rm -f /tmp/node.tar.xz
 
-# Install Bun
-RUN npm install -g bun@${BUN_VERSION} \
-    && bun --version
-
 # Install PowerShell
 RUN curl -fsSL -o /tmp/powershell.tar.gz \
     "https://github.com/PowerShell/PowerShell/releases/download/v${PWSH_VERSION}/powershell-${PWSH_VERSION}-linux-x64.tar.gz" \
@@ -53,22 +93,9 @@ RUN curl -fsSL -o /usr/local/bin/ttyd \
     "https://github.com/tsl0922/ttyd/releases/download/${TTYD_VERSION}/ttyd.x86_64" \
     && chmod +x /usr/local/bin/ttyd
 
-# Build OpenCode CLI from source
-COPY opencode /opt/opencode-src
-WORKDIR /opt/opencode-src
-
-# Configure git for any workspace dependencies that use git URLs
-RUN git config --global url."https://github.com/".insteadOf "ssh://git@github.com/"
-
-# Install dependencies and build OpenCode CLI
-ENV HUSKY=0
-RUN bun install 2>&1 \
-    && bun run ./packages/opencode/script/build.ts --single
-
-# Copy the built binary to /usr/local/bin
-RUN cp /opt/opencode-src/packages/opencode/dist/opencode-linux-x64/bin/opencode /usr/local/bin/opencode \
-    && chmod +x /usr/local/bin/opencode \
-    && opencode --version
+# Copy the built OpenCode binary from builder stage
+COPY --from=opencode-builder /opt/opencode-src/packages/opencode/dist/opencode-linux-x64/bin/opencode /usr/local/bin/opencode
+RUN chmod +x /usr/local/bin/opencode && opencode --version
 
 # Setup PowerShell profile
 RUN mkdir -p /root/.config/powershell