refactor: Reorganize docs folder structure for clarity and version management (PR 3c)

Reorganize documentation following AGENTS.md v16.0 governance (traceability, reproducibility):

Structure changes:
- CURRENT/ (new)
  ├─ 00~08.md (v16.0 standards, renamed for clarity)
  └─ CATALOGS/ (9 CSV files: WBS, decision log, debt register, matrices, catalogs)

- LEGACY/ (new, read-only archives)
  ├─ v11/ (original baseline + hardening analysis)
  ├─ v12~v15/ (.gitkeep + README for future archiving)

- DECISIONS/ (new, ready for ADR usage)
- TEMPLATES/ (existing, unchanged)

Deletions (consolidated into CURRENT/):
- v16_0/ folder (files migrated)
- hardening/ folder (contents → LEGACY/v11/)
- Root-level v11 files (00~07.md, CSV)

Renames (for clarity):
- 00_EXECUTIVE_REFERENCE_IMPLEMENTATION.md → 00_EXECUTIVE.md
- 01_BRUTAL_ROLE_AUDIT.md → 01_ROLE_AUDIT.md
- 02_FRONTEND_ADAPTER_CRUD_STANDARD.md → 02_FE_ADAPTER.md
- 03_BACKEND_DATA_SCHEDULER_STANDARD.md → 03_BE_DATA.md
- 04_ALGORITHM_MODEL_GOVERNANCE.md → 04_ALGORITHM.md
- 05_PROCESS_VIBE_DEBT_CONTROL.md → 05_PROCESS_VIBE_DEBT.md
- 06_VALIDATION_TRUTH.md → 06_VALIDATION.md
- 07_PACKAGE_ATTACHMENT_POLICY.md → 07_PACKAGE_POLICY.md

Updates:
- docs/INDEX.md (complete rewrite with navigation)
- LEGACY/ folders with README + .gitkeep

Benefits:
✅ Clear version management (v16.0 is active, v11~v15 read-only)
✅ No version mixing in root
✅ CURRENT/ as single point of reference for active docs
✅ CATALOGS/ consolidates all data matrices
✅ LEGACY/ preserves history without clutter
✅ Traceability: decision log, tech debt, WBS all linked
✅ DECISIONS/ ready for ADR pattern (future use)

Sync with root:
- CLAUDE.md references: docs/CURRENT/, docs/INDEX.md ✅
- AGENTS.md references: docs/CURRENT/, traceability ✅
- README.md: Document guide links updated ✅

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

docs/INDEX.md

@@ -1,48 +1,124 @@
-# Documentation Index
+# Documentation Index (v16.0)
 
-## Core Development Guides
+**Latest docs:** [`CURRENT/`](CURRENT/) — Main reference for development
+**Legacy:** [`LEGACY/`](LEGACY/) — Archived versions (read-only)
+**Root guides:** [`../CLAUDE.md`](../CLAUDE.md), [`../AGENTS.md`](../AGENTS.md)
+
+---
+
+## 🔥 Active Documentation (CURRENT/)
+
+### Development Standards
 
 | Document | Purpose | Audience |
 |----------|---------|----------|
-| [`../CLAUDE.md`](../CLAUDE.md) | Claude Code development guide | AI-assisted developers |
-| [`../AGENTS.md`](../AGENTS.md) | AI coding constitution v16.0 | All developers |
-| [`03_ARCHITECTURE_BE_FE.md`](03_ARCHITECTURE_BE_FE.md) | System architecture (Modular Monolith, Vertical Slice) | Architects, Backend engineers |
-| [`06_VIBE_CODING_GUARDRAILS.md`](06_VIBE_CODING_GUARDRAILS.md) | AI work protocols, guardrails | All developers using Claude |
-| [`07_VALIDATION_GATES.md`](07_VALIDATION_GATES.md) | Production readiness criteria | QA, Release managers |
+| [`CURRENT/00_EXECUTIVE.md`](CURRENT/00_EXECUTIVE.md) | Project rationale & v16.0 delta | Architects, PMs |
+| [`CURRENT/01_ROLE_AUDIT.md`](CURRENT/01_ROLE_AUDIT.md) | Role-based governance audit | All developers |
+| [`CURRENT/02_FE_ADAPTER.md`](CURRENT/02_FE_ADAPTER.md) | Frontend adapter & CRUD standard | Frontend engineers |
+| [`CURRENT/03_BE_DATA.md`](CURRENT/03_BE_DATA.md) | Backend data & scheduler standard | Backend engineers |
+| [`CURRENT/04_ALGORITHM.md`](CURRENT/04_ALGORITHM.md) | **Algorithm & model governance** | Data scientists, Quants |
+| [`CURRENT/05_PROCESS_VIBE_DEBT.md`](CURRENT/05_PROCESS_VIBE_DEBT.md) | Process, Vibe coding, debt control | All developers |
+| [`CURRENT/06_VALIDATION.md`](CURRENT/06_VALIDATION.md) | Validation truth & gates | QA, Release managers |
+| [`CURRENT/07_PACKAGE_POLICY.md`](CURRENT/07_PACKAGE_POLICY.md) | Release package & attachment policy | DevOps, Architects |
+| [`CURRENT/08_RESTART_PLAN.md`](CURRENT/08_RESTART_PLAN.md) | 20-day restart/onboarding plan | Project managers |
 
-## Executive & Planning
+### Catalogs & Matrices
 
-| Document | Purpose |
-|----------|---------|
-| [`00_EXECUTIVE_PROPOSAL.md`](00_EXECUTIVE_PROPOSAL.md) | High-level project rationale |
-| [`01_SOURCE_AUDIT.md`](01_SOURCE_AUDIT.md) | Source code assessment |
-| [`02_ALGORITHM_REFACTORING.md`](02_ALGORITHM_REFACTORING.md) | Algorithm improvement strategy |
+All in [`CURRENT/CATALOGS/`](CURRENT/CATALOGS/):
 
-## Tech Debt & Maintenance
+| File | Purpose |
+|------|---------|
+| `WBS_MASTER.csv` | 576 work items, traceability |
+| `DECISION_LOG.csv` | 80+ architectural decisions |
+| `TECH_DEBT_REGISTER.csv` | All tech debt tracked |
+| `TRACEABILITY_MATRIX.csv` | Feature ↔ test ↔ evidence |
+| `VALIDATION_MATRIX.csv` | Gate status, readiness checklist |
+| `FE_COMPONENT.csv` | 43 UI components, versions |
+| `JOB_CATALOGUE.csv` | 26 background jobs |
+| `SOURCE_COVERAGE.csv` | Code coverage & safety |
+| `PACKAGE_CONTENTS.csv` | Release artifact manifest |
 
-| Document | Purpose |
-|----------|---------|
-| [`../TECH_DEBT_REGISTER.md`](../TECH_DEBT_REGISTER.md) | Tech debt tracking (Impact/Effort matrix) |
+### Reference Materials
 
-## Reference Documents
+- [`CURRENT/K-ArtSell_Aegis_v16_0_*.docx`](CURRENT/) — Full proposal document
+- [`CURRENT/DOCX_A11Y_V16_0.json`](CURRENT/) — Accessibility audit results
 
-- `contracts/` — Data and API contracts (UI adapter, schedules, events)
-- `templates/` — Vertical Slice, Hangfire job, SQL scaffolds
-- `tools/` — Scaffold generators, validators
+---
 
-## Quick Links
+## 🗂️ Legacy Archives (LEGACY/)
+
+**Status:** Read-only (no longer maintained)
+
+| Version | Location | Note |
+|---------|----------|------|
+| v15 | `LEGACY/v15/` | Previous implementation |
+| v14 | `LEGACY/v14/` | Previous implementation |
+| v13 | `LEGACY/v13/` | Previous implementation |
+| v12 | `LEGACY/v12/` | Previous implementation |
+| v11 | `LEGACY/v11/` | Original baseline + hardening analysis |
+
+Use for **historical context only**. All current work references `CURRENT/`.
+
+---
+
+## 📋 Root-Level Guides
+
+Reference at project root (not in docs/):
+
+- [`../CLAUDE.md`](../CLAUDE.md) — Claude Code development (setup, build, test, Gitea API)
+- [`../AGENTS.md`](../AGENTS.md) — AI coding constitution v16.0 (13 decision criteria, checklist, anti-patterns)
+- [`../README.md`](../README.md) — Project overview & document navigation
+- [`../TECH_DEBT_REGISTER.md`](../TECH_DEBT_REGISTER.md) — Active debt tracking (Impact/Effort matrix, paydown targets)
+
+---
+
+## 🚀 Quick Start
 
 **For your first change:**
-1. Read [`../CLAUDE.md`](../CLAUDE.md) (setup, build, test)
-2. Review [`../AGENTS.md`](../AGENTS.md) decision checklist
-3. Check [`03_ARCHITECTURE_BE_FE.md`](03_ARCHITECTURE_BE_FE.md) for module boundaries
-4. Reference [`06_VIBE_CODING_GUARDRAILS.md`](06_VIBE_CODING_GUARDRAILS.md) before AI code requests
+1. Read [`../CLAUDE.md`](../CLAUDE.md) — local setup, build/test commands
+2. Review [`../AGENTS.md`](../AGENTS.md) — work decision checklist (13 items)
+3. Check [`CURRENT/01_ROLE_AUDIT.md`](CURRENT/01_ROLE_AUDIT.md) — role-based governance
+4. Reference [`CURRENT/02_FE_ADAPTER.md`](CURRENT/02_FE_ADAPTER.md) or [`CURRENT/03_BE_DATA.md`](CURRENT/03_BE_DATA.md) — architecture
 
 **For architectural decisions:**
-- Module communication: [`03_ARCHITECTURE_BE_FE.md`](03_ARCHITECTURE_BE_FE.md#2-vertical-slice-standard)
-- Observability: [`../CLAUDE.md`](../CLAUDE.md#observability)
-- Tech debt: [`../TECH_DEBT_REGISTER.md`](../TECH_DEBT_REGISTER.md)
+- **Algorithm/Model:** [`CURRENT/04_ALGORITHM.md`](CURRENT/04_ALGORITHM.md)
+- **All decisions:** [`CURRENT/CATALOGS/DECISION_LOG.csv`](CURRENT/CATALOGS/DECISION_LOG.csv)
+- **Tech debt:** [`../TECH_DEBT_REGISTER.md`](../TECH_DEBT_REGISTER.md) (root level)
 
 **For validation & release:**
-- Gates to pass: [`07_VALIDATION_GATES.md`](07_VALIDATION_GATES.md)
-- Readiness checklist: [`../AGENTS.md`](../AGENTS.md#work-decision-checklist)
+- **Gates:** [`CURRENT/06_VALIDATION.md`](CURRENT/06_VALIDATION.md)
+- **Package contents:** [`CURRENT/CATALOGS/PACKAGE_CONTENTS.csv`](CURRENT/CATALOGS/PACKAGE_CONTENTS.csv)
+- **Release artifacts:** [`CURRENT/`](CURRENT/) (proposal DOCX, A11Y audit JSON)
+
+---
+
+## 📚 Templates
+
+See [`TEMPLATES/`](TEMPLATES/) for reusable templates:
+- ADR.md — Architectural Decision Record
+- SLICE_SPEC.md — Vertical Slice specification
+- TECH_DEBT_ITEM.md — Tech debt entry template
+- RUNBOOK.md — Operations runbook template
+- And 7 more...
+
+---
+
+## 🔗 Navigation
+
+```
+Root
+├─ CLAUDE.md (← Developer starts here)
+├─ AGENTS.md
+├─ README.md
+├─ TECH_DEBT_REGISTER.md
+└─ docs/
+   ├─ INDEX.md (← You are here)
+   ├─ CURRENT/ (← Active v16.0 docs)
+   │  ├─ 00~08.md (8 standards)
+   │  ├─ CATALOGS/ (9 CSV files)
+   │  └─ *.docx, *.json (release artifacts)
+   ├─ LEGACY/ (read-only archives)
+   │  ├─ v11, v12, v13, v14, v15
+   ├─ TEMPLATES/
+   └─ (tools, contracts are sibling dirs)
+```