Corrupted ZIM files cause a native C++ abort (ZimFileFormatError) that
bypasses JS try/catch and kills the process. Add magic number validation
before passing files to @openzim/libzim so invalid files are skipped
gracefully. Also deduplicate Ollama download progress broadcasts — both
within a single stream (skip unchanged percentages) and across concurrent
callers (share one download promise per model).
Co-authored-by: aegisman <aegis@manicode.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
