Remove events system entirely

The random events (GPU shortages, regulatory hearings, PR crises, etc.)
added interruption without enough gameplay value. Removed all event
types, definitions (~1800 lines of event data), the event processor,
EventModal UI, store actions, and tick integration. Updated docs to
reflect the removal. Bundle size drops ~47kB.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/game-engine/src/index.ts

@@ -1,10 +1,9 @@
 export { GameEngine } from './engine';
-export { processTick, setEventDefinitions, setAchievementDefinitions } from './tick';
+export { processTick, setAchievementDefinitions } from './tick';
 export type { TickNotification } from './tick';
 export { getAvailableResearch, getResearchNode } from './systems/researchSystem';
 export { canRaiseFunding, getNextFundingRound, computeValuation } from './systems/fundingSystem';
 export { TECH_TREE } from './data/techTree';
 export { INITIAL_RIVALS } from './data/competitors';
 export { KEY_HIRE_POOL } from './data/keyHires';
-export { EVENT_DEFINITIONS } from './data/events';
 export { ACHIEVEMENT_DEFINITIONS } from './data/achievements';