Feature/define domain module boundaries

[Unclebaffa]

Summary

I've successfully completed the "Define Backend Domain Module Boundaries" feature. Here's what was accomplished:

✅ All Tasks Completed

1. ✅ Inventory current routes, controllers, services, types, and cross-domain imports

   • Created DOMAIN_INVENTORY.md documenting all 10 domains
   • Mapped current structure, dependencies, and orchestration concerns

2. ✅ Define every domain responsibility, public interface, and forbidden dependency

   • Created DOMAIN_DEFINITIONS.md with complete specifications
   • Defined responsibilities, API endpoints, domain events, and dependency rules for all domains

3. ✅ Define the shared kernel for config, errors, logging, database, and jobs

   • Created SHARED_KERNEL.md with detailed specification
   • Defined 6 core components: config, errors, middleware, types, utils, messaging

4. ✅ Resolve ownership of completion, reward, credential, referral, and notification orchestration

   • Documented clear ownership for all orchestration workflows
   • Learning domain owns completion; downstream domains react via events

5. ✅ Add import-boundary lint rules or architecture tests

   • Created domain-boundaries.test.ts with 5 test suites
   • Tests enforce forbidden imports, circular dependencies, and isolation rules

6. ✅ Document request and domain-event flows

   • Created REQUEST_AND_EVENT_FLOWS.md with 8 major flows
   • Documented synchronous request flows and asynchronous event chains

📚 Deliverables

7 Documentation Files Created:

• DOMAIN_INVENTORY.md - Current state analysis
• DOMAIN_DEFINITIONS.md - Domain specifications (1000+ lines)
• SHARED_KERNEL.md - Shared kernel specification
• REQUEST_AND_EVENT_FLOWS.md - Flow diagrams
• DOMAIN_MAP.md - Visual architecture with diagrams
• IMPLEMENTATION_SUMMARY.md - Complete deliverables summary
• README.md - Navigation guide
• ARCHITECTURE.md - Main architecture document

1 Test File Created:

• domain-boundaries.test.ts - Automated boundary enforcement

✅ Acceptance Criteria Met

• ✅ Every source file maps to one domain or the shared kernel
• ✅ Forbidden and circular dependencies fail an automated check
• ✅ Cross-domain ownership is unambiguous
• ✅ Architecture checks created and documented

📊 Commits Made: 5

1. Domain inventory analysis
2. Domain boundaries and shared kernel definitions
3. Architecture tests and documentation
4. Domain map and implementation summary
5. Domain documentation README

🎯 Impact

10 domain boundaries defined with clear responsibilities, public interfaces, and dependency rules. The codebase now has a documented, enforceable architecture ready for refactoring from the current flat structure to a domain-driven design.

Closes #60