Fix dimension matrix showing no colors (hash-based lookup broken)

DIM_DATA was keyed by hardcoded commit short IDs from a single run. Every tour regeneration produces fresh SHA-256 hashes, so all lookups returned undefined and no colors rendered.

Replace the static hash-to-dims map with getDims(commit) and getConflicts(commit) — message-pattern functions that are stable across re-runs — and call _initDimMaps() at init time to populate DIM_DATA and DIM_CONFLICTS from the live DATA before rendering.