fix: pre-install spacy en_core_web_sm model at build time (root site-packages)

Dockerfile

@@ -30,6 +30,11 @@ RUN uv pip install --system --no-cache \
     -r requirements-ci-english.txt \
     -r requirements-ci-hindi.txt
 
+# Pre-install the spacy model into system site-packages (as root).
+# At runtime the app runs as non-root 'user', so pip downloads
+# the model into user site-packages which spacy can't find.
+RUN python -m spacy download en_core_web_sm
+
 # Now create non-root user (HF Spaces requirement)
 RUN useradd -m -u 1000 user
 USER user