docs: add comprehensive spec compliance development design document

Analyzes @objectstack/spec v2.0.4 system protocol (26 schemas, 22 kernel schemas)
against current ObjectOS implementation (14 plugins). Identifies 14 gaps in system
protocol coverage, proposes 8 new plugins, 7 existing plugin improvements, and
5 upstream spec improvement proposals (SPEC-001 through SPEC-005).

Key findings:
- 13/18 CoreServiceName services registered (72%)
- 5/18 fully compliant (28%)
- Missing: logging, tracing, search, compliance, tenant, queue, migration, analytics, graphql, ai, license
- 4-phase implementation roadmap (~77-117 days total)

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot