fix: SSH key display and mkdir in Dockerfile

- Fetch SSH public key every time auth section opens (was only fetching
  once and caching failures)
- Add mkdir for SSH key directory in Dockerfile.agent

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile.agent

@@ -33,6 +33,9 @@ RUN pip3 install --break-system-packages ruff
 
 COPY --from=builder /app/target/release/compliance-agent /usr/local/bin/compliance-agent
 
+# Ensure SSH key directory exists
+RUN mkdir -p /data/compliance-scanner/ssh
+
 EXPOSE 3001 3002
 
 ENTRYPOINT ["compliance-agent"]