The exact open-locating-dominating density of the kagome grid

The minimum open-locating-dominating density of the infinite kagome (trihexagonal, hexagon-triangle, 3.6.3.6) grid is 2/5. An explicit periodic construction selects 12 of 30 representative vertices and attains the known universal degree-four lower bound. The finite verifier reconstructs adjacency from shared honeycomb endpoints and checks 360 directed comparisons with absolute-coordinate signatures. The written proof includes the lower counting bound and the infinite-plane density argument.