Keep monster alive long enough to leave the water

[jquast]

makeMonster() places the monster on a river tile, and doMonsterSprite() ends a monster whose hot spot is over water, or one that comes within 60 px of its spawn point, so a spawned monster died almost immediately.

$ make -C packages/micropolis-engine install
$ cd apps/micropolis
$ node_modules/.bin/tsx -e "import { loadMicropolisMainModule } from './src/lib/wasm/node.ts'; import { createNoopJsCallback } from './src/lib/wasm/callbacks'; (async () => { const e = await loadMicropolisMainModule(); const ticks = []; for (let run = 0; run < 8; run += 1) { const m = new e.Micropolis(); m.setCallback(createNoopJsCallback(e), {}); m.init(); m.loadCity('/cities/deadwood.cty'); m.setEnableDisasters(true); m.makeMonster(); let died = -1; for (let i = 1; i <= 100; i += 1) { m.simTick(); if (!m.getActiveSprites().some((s) => s.type === 5)) { died = i; break; } } ticks.push(died < 0 ? '>100' : died); m.delete(); } console.log('death ticks:', ticks.join(', ')); })();"
death ticks: 27, 27, 21, 47, 1, 1, 1, 1

The same eight spawns after this commit:

death ticks: >100, >100, >100, >100, >100, >100, 78, >100

simcity-monster-fixed.mp4

Depends on #15 (the loader fix) and #20 (the monster bindings) to run the commands above.