feat: add Claude Code native implementation with multi-agent architecture

[anhyobin]

Summary

Add Claude Code-native AIDLC implementation using agents, skills, hooks, and rules. This provides the same AIDLC methodology with system-level role enforcement, on-demand context loading, and automated workflow management.

• 14 skills (one per AIDLC stage, invoked as /aidlc-* slash commands)
• 4 agents with tool isolation (analyst, architect, developer, reviewer)
• 6 cross-cutting rules (content validation, error handling, terminology, workflow changes, 2 conditional extensions)
• 2 hooks (SessionStart auto-detection, SubagentStop audit logging)

What Changed

New directory: platforms/claude-code/ (or location TBD by maintainers)

.claude/
├── CLAUDE.md                     # Lightweight routing (~73 lines)
├── settings.json                 # Hooks + permissions
├── agents/  (4 files)            # Role-based agents with tool restrictions
├── rules/   (6 files)            # Cross-cutting rules + conditional extensions
└── skills/  (14 directories)     # One skill per AIDLC stage

Plus: README.md, LICENSE (MIT-0)

Why

Claude Code has native capabilities that the single rule-file approach cannot leverage:

Capability	Rule File	Native
Tool isolation	"Don't modify code" (text)	disallowedTools: [Write, Edit] (system)
Context efficiency	538 lines always loaded	73 lines + on-demand skills
Session resumption	Manual state check	SessionStart hook auto-detects
Audit logging	Manual recording	SubagentStop hook auto-records
Extension loading	Always loaded	Conditional via paths frontmatter

Testing

Scenario: Serverless Order Management API (Cognito, Lambda, DynamoDB, SQS, EventBridge, Stripe integration. 4 units, TypeScript/CDK.)

Method: 42 agent evaluations across all 14 AIDLC stages, comparing 3 approaches:

Approach	Assertions Passed	Pass Rate
Claude Code Native	76/76	100%
Upstream Rule File	73/76	96.1%
No Guidance	54/71	76.1%

Native outperforms upstream in:

• functional: Technology-agnostic constraint enforcement (upstream leaked specific service names into business logic design)
• gate: 2-phase pipeline structure compliance (upstream merged code review and testing into a single undifferentiated pass)

76 assertions cover: structural compliance (question format, [Answer]: tags, X) Other options, categorized questions), methodology adherence (4-dimension analysis, INVEST criteria, EXECUTE/SKIP decisions, GO/NO-GO + PASS/FAIL verdicts), and artifact completeness. The implementation is language-agnostic -- output language follows the user's language automatically.

Full benchmark data: aidlc-skills-workspace/full-eval/benchmark.json

Upstream Compatibility

• Same three-phase lifecycle, stage sequence, and gate rules
• Same question file format and artifact structure (aidlc-docs/)
• Extensions aligned with security-baseline and property-based-testing
• Cross-cutting rules derived from upstream common/ (content-validation, error-handling, terminology, workflow-changes)

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