fix(docker): reorder COPY commands for HuggingFace build context

PROBLEM:
- HuggingFace build failing with: '/huggingface/supervisord.conf': not found
- Docker layer caching was invalidating when backend code changed
- Config files copied AFTER backend, causing cache miss

FIX:
- Reordered COPY commands: configs → frontend → backend
- Ensures HuggingFace configs cached early in build
- Optimizes Docker layer caching (least-to-most frequently changed)

BENEFITS:
- Fixes HuggingFace deployment build failure
- Better cache utilization (faster builds)
- More resilient to code changes

huggingface/Dockerfile

@@ -38,16 +38,19 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 # Stage 2: Copy Application Code
 # ==========================================
 
-# Copy backend code
-COPY backend/ /app/backend/
+# Copy requirements.txt first (changes least frequently)
 COPY requirements.txt /app/
 
+# Copy HuggingFace specific configs BEFORE application code
+# (these rarely change, so they should be cached early)
+COPY huggingface/nginx.conf /etc/nginx/nginx.conf
+COPY huggingface/supervisord.conf /etc/supervisor/conf.d/supervisord.conf
+
 # Copy frontend code
 COPY frontend/ /app/frontend/
 
-# Copy HuggingFace specific configs
-COPY huggingface/nginx.conf /etc/nginx/nginx.conf
-COPY huggingface/supervisord.conf /etc/supervisor/conf.d/supervisord.conf
+# Copy backend code (changes most frequently, so copy last)
+COPY backend/ /app/backend/
 
 # ==========================================
 # Stage 3: Install Python Dependencies