fix: YARP routing, EnsureCreated, and CorrelationIdMiddleware

[devin-ai-integration]

Summary

Three fixes (plus two bonus fixes discovered during testing) to get all microservices working correctly through the YARP API gateway:

1. YARP Gateway Routing (src/ApiGateway/appsettings.json): Replaced PathRemovePrefix transforms with PathPattern so public plural paths (e.g. /api/customers) are correctly rewritten to backend singular controller routes (e.g. /api/customer).

2. EnsureCreated() for 4 services: Added the EnsureCreated() block (already present in Notification) to Identity, Customer, Order, and Product Program.cs files so their database schemas are auto-created on startup. Added retry logic (up to 5 retries with 2s delay) to all 5 services to handle PostgreSQL startup race conditions.

3. CorrelationIdMiddleware: Registered Shared.Infrastructure.Middleware.CorrelationIdMiddleware in all 5 service Program.cs files and the API Gateway. Added the Shared.Infrastructure project reference to ApiGateway.csproj (the 5 services already had it).

4. Fixed Shared project reference paths (bonus): All service .csproj files had incorrect relative paths to Shared projects (../../Shared/ instead of ../../../Shared/). Fixed to resolve correctly in both local and Docker builds.

5. Updated ApiGateway Dockerfile (bonus): Added COPY commands for Shared.Infrastructure project files so the gateway can build with the new project reference.

Verified locally with Docker Compose:

• All 8 containers start and stay running (including retry for PostgreSQL readiness)
• Gateway routes: /api/customers, /api/orders, /api/products, /api/identity, /api/notifications all return correct responses
• Direct service access on ports 5001-5005 all working
• X-Correlation-ID header present in gateway responses

Review & Testing Checklist for Human

• Run cd src && docker compose up --build — all 8 containers should start and stay healthy
• curl http://localhost:5000/api/customers returns {"service":"Customer","status":"scaffold"}
• curl http://localhost:5000/api/orders returns {"service":"Order","status":"scaffold"}
• curl http://localhost:5000/api/products returns {"service":"Product","status":"scaffold"}
• curl -v http://localhost:5000/api/customers 2>&1 | grep X-Correlation-ID returns a correlation ID header

Notes

• The gateway keeps public-facing plural paths but rewrites to singular backend controller routes via PathPattern.
• Retry logic on EnsureCreated() prevents services from crashing when PostgreSQL isn't ready yet (race condition with depends_on which only waits for container start, not readiness).

Link to Devin session: https://partner-workshops.devinenterprise.com/sessions/d9b6eee197954b38ba1055661081c0ca

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[devin-ai-integration]

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.