🔄 fix: simplify Docker cache approach and integrate properly

Dockerfile.build

@@ -31,9 +31,16 @@ RUN go install github.com/swaggo/swag/cmd/swag@latest && \
 COPY go.mod go.sum ./
 RUN go mod download && go mod verify
 
-# Copy the rest of the source (this happens in CI)
-# COPY . .
+# Simple build environment - source code is mounted at runtime
+WORKDIR /workspace
 
-# Build command (will be run in CI)
-# RUN go build -o /out/server ./cmd/server && \
-#     go build -o /out/greet ./cmd/greet
+# Install basic CI tools
+RUN apk add --no-cache \
+    git \
+    bash \
+    make \
+    gcc \
+    musl-dev
+
+# Pre-download common Go tools
+RUN go install github.com/swaggo/swag/cmd/swag@latest