Add Week 3 polish and late-game features

VC funding system (seed through IPO with requirements gating), 15
achievements with engine checker, model tuning presets and unlockable
sliders, overload policy controls, open-source mechanic with reputation
boost, enhanced Recharts analytics (subscriber/reputation/revenue vs
expenses charts), M&A acquisition system, sidebar NEW badges on era
transitions, tutorial hints, and wired-up settings toggles.

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

packages/game-engine/src/index.ts

@@ -1,8 +1,10 @@
 export { GameEngine } from './engine';
-export { processTick, setEventDefinitions } from './tick';
+export { processTick, setEventDefinitions, 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';