Force Docker rebuild with cache-bust ENV to deploy IST timestamp fix

Dockerfile

@@ -18,6 +18,9 @@ WORKDIR /app
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
+# Cache-bust: increment to force a fresh COPY on HF Spaces
+ENV APP_BUILD=2
+
 # Copy application code
 COPY . .