docs: comprehensive gap analysis of spec-implementation mismatches

Identified 30+ gaps across NetEngine codebase:

Major findings:
- 14+ spec fields declared but never implemented (DNSSEC, CRL, OCSP,
  intermediate CA, real internet gateway, cross-world federation, AND profiles)
- 4 event queues referenced but not defined in queue registry (runtime risk)
- 4+ missing API endpoints for service/gateway/AND profile management
- 7 deprecated state fields accumulating bloat
- 8+ features with zero test coverage
- Phase 9 missing world_services_output prerequisite
- world_spec not updated after /api/v1/reload

Severity breakdown:
- 🔴 Critical: 4 infrastructure gaps (PKI, gateway, AND, event queues)
- 🟡 Medium: 4 API/phase gaps
- 🟢 Low: 7 tech debt items

Remediation roadmap provided with priorities and effort estimates.
See docs/COMPREHENSIVE_GAP_ANALYSIS.md for full details and file references.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GsxYTYj8aKUsN7W6S9FAcE

Author: claude