- screen transitions snapshot the previous frame (ratatui swaps buffers
after draw, so the old snapshot was always blank); frame loop extracted
into a testable Runner
- .city loading rejects structurally inconsistent files: Grid deserialize
checks size vs data, load_city checks header vs body and runs
City::validate (now also checks Net link endpoints)
- saving from the map hands the live map screen back instead of a fresh
explore screen
- signage glyphs covered by the unicode-width test
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Also guarantees one building per district and repairs interiors split
by crossing partitions, both found by the new validation.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
