feat: [ECSoC_2026] Feature: Studio Corporate Bond Issuance & Credit Rating Engine

[Babin123456]

Problem

Studios requiring large capital injections for mega-budget blockbuster productions rely solely on basic bank loans, lacking an institutional bond market with credit ratings (AAA to CCC), yield interest calculations, coupon payments, and debt default protections.

Current Behavior

No corporate bond market or credit evaluation system exists to calculate studio interest rates based on debt-to-equity leverage.

Why This Improvement Is Needed

Adding corporate debt financing provides realistic financial leverage mechanics where high-reputation studios issue low-yield AAA bonds, while distressed studios must issue high-yield junk bonds or face credit downgrades.

Proposed Solution

1. Create StudioFinanceBond Mongoose schema with credit rating grades, interest percentages, duration weeks, and weekly coupon payment schedules.
2. Build bondMarketEngine.js calculating credit ratings based on studio net equity and prestige, plus weekly coupon payment processing.
3. Expose Express API routes (/api/bond-market) for credit evaluation, bond issuance, and weekly processing.
4. Add unit test suite in bondMarketEngine.test.js.

Expected Outcome

• Credit rating evaluation based on studio net equity.
• Dynamic interest yield adjustment and weekly interest deduction.

Additional Notes

Prevents negative cash balance exploit via insolvency credit rating restrictions.