docs: add unified logging system documentation and CI/CD integration (refs #87)

- Update staging workflow to use LOG_LEVEL=DEBUG
- Create docs/LOGGING.md with unified logging documentation
- Delete docs/UX-DEBUGGING.md (replaced by LOGGING.md)
- Update architecture to 9-container (6 app + 3 logging)
- Update CLAUDE.md, README.md, docs/README.md, docs/CLAUDE.md
- Update docs/PLATFORM-SERVICES.md deployment section

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/CLAUDE.md

@@ -5,7 +5,7 @@
 | File | What | When to read |
 | ---- | ---- | ------------ |
 | `README.md` | Documentation hub and navigation | Starting point for any docs |
-| `PLATFORM-SERVICES.md` | 5-container architecture overview | Understanding system topology |
+| `PLATFORM-SERVICES.md` | 9-container architecture overview | Understanding system topology |
 | `ARCHITECTURE-OVERVIEW.md` | Detailed architecture documentation | Deep dive into system design |
 | `DATABASE-SCHEMA.md` | Database table definitions | Schema changes, data modeling |
 | `DATABASE-MIGRATION.md` | Migration procedures | Running or writing migrations |
@@ -17,5 +17,5 @@
 | `BUILD-SERVER-SETUP.md` | Build server setup | Infrastructure setup |
 | `AUDIT.md` | Audit documentation | Security audits, compliance |
 | `MVP-COLOR-SCHEME.md` | Color scheme reference | UI styling decisions |
-| `UX-DEBUGGING.md` | UX debugging techniques | Debugging UI issues |
+| `LOGGING.md` | Unified logging system | Log levels, correlation IDs, Grafana |