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Both functions previously returned Option despite their invariants guaranteeing a value: active_view always names an existing view (maintained by new/switch_view/delete_view), and axis_of only returns None for categories never registered with the view (a programming error). Callers no longer need to handle the impossible None case, eliminating ~15 match/if-let Option guards across app.rs, dispatch.rs, grid.rs, tile_bar.rs, and category_panel.rs. Also adds Model::evaluate_f64 (returns 0.0 for empty cells) and collapses the double match-on-axis pattern in tile_bar/category_panel into a single axis_display(Axis) helper. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>