feat(epic1): complete OpenTelemetry integration and add verification documentation

Story 1.6: OpenTelemetry Distributed Tracing
- Implemented tracer initialization with stdout (dev) and OTLP (prod) exporters
- Added HTTP request instrumentation via Gin middleware
- Integrated trace ID correlation in structured logs
- Added tracing configuration to config files
- Registered tracer provider in DI container

Documentation and Setup:
- Created Docker Compose setup for PostgreSQL database
- Added comprehensive Epic 1 summary with verification instructions
- Added Epic 0 summary with verification instructions
- Linked summaries in documentation index and epic READMEs
- Included detailed database testing instructions
- Added Docker Compose commands and troubleshooting guide

All Epic 1 stories (1.1-1.6) are now complete. Story 1.7 depends on Epic 2.

docs/content/index.md

@@ -43,8 +43,8 @@ All architectural decisions are documented in [ADR records](adr/README.md), orga
 
 ### 📝 Implementation Tasks
 Detailed task definitions for each epic are available in the [Stories section](stories/README.md):
-- Epic 0: Project Setup & Foundation
-- Epic 1: Core Kernel & Infrastructure
+- **[Epic 0: Project Setup & Foundation](stories/epic0/README.md)** - [Implementation Summary](stories/epic0/SUMMARY.md)
+- **[Epic 1: Core Kernel & Infrastructure](stories/epic1/README.md)** - [Implementation Summary](stories/epic1/SUMMARY.md)
 - Epic 2: Authentication & Authorization
 - Epic 3: Module Framework
 - Epic 4: Sample Feature Module (Blog)