docs: Foundation Freeze v1.0 + directory reorganization

- FOUNDATIONS-v1.0.md:
  - Freeze contract for Landvex Design System
  - Scope: Motion, AI Principles, Semantic Colors, Grid, Elevation, Typography, RFC Template, Definition of Done
  - Reference components: Button, Input, Select, Card (all ~83%)
  - Invariants: token rules, component rules, accessibility rules, AI rules
  - Change policy: no new foundation concepts without v2.0 RFC
  - Versioning: 1.0.x patches, 1.x.0 new components, 2.0.0 new foundations
  - Compatibility matrix for all foundations and components

- Directory reorganization:
  - docs/design/foundations/ → frozen foundation documents
  - docs/design/components/ → component RFCs
  - docs/design/README.md → navigation and structure

- Foundation documents moved:
  - TOKEN_PHILOSOPHY, SEMANTIC_COLOR_SYSTEM, GRID_ELEVATION
  - AI_DESIGN_PRINCIPLES, COMPONENT_TEMPLATE, RFC_DEFINITION_OF_DONE
  - DESIGN_ANTI_PATTERNS, COMPONENT_DECISION_TREE, GLOSSARY
  - BRAND_PALETTE, RELEASE_DEFINITION, SEMANTIC_COLOR_SYSTEM_REVIEW

- Component RFCs moved:
  - RFC-002-Input, RFC-003-Select, RFC-004-Card

Rationale: Clear separation between foundations (stable platform) and
components (built on top). Foundations v1.0 frozen — components can be
added freely within v1.x, but foundations require v2.0 RFC to change.
This prevents gradual erosion of the design system architecture.

docs/design/README.md

@@ -0,0 +1,43 @@
+# Landvex Design System
+
+**Documentation Structure**
+
+```
+docs/design/
+├── README.md                    # This file
+├── COMPLIANCE_MATRIX.md         # Component readiness tracking
+├── LANDVEX_DESIGN_CONSTITUTION.md  # UX principles (Level 3)
+├── LANDVEX_DESIGN_SPECIFICATION.md # Technical contract (Level 5)
+├── foundations/                 # Frozen foundations
+│   ├── FOUNDATIONS-v1.0.md      # Freeze contract
+│   ├── TOKEN_PHILOSOPHY.md      # Token rules
+│   ├── SEMANTIC_COLOR_SYSTEM.md # Color tokens
+│   ├── GRID_ELEVATION.md        # Layout & depth
+│   ├── AI_DESIGN_PRINCIPLES.md  # AI governance
+│   ├── COMPONENT_TEMPLATE.md    # RFC template
+│   ├── RFC_DEFINITION_OF_DONE.md # Quality gate
+│   ├── DESIGN_ANTI_PATTERNS.md  # Forbidden patterns
+│   ├── COMPONENT_DECISION_TREE.md # Selection guide
+│   ├── GLOSSARY.md              # Common language
+│   ├── BRAND_PALETTE.md         # Brand colors
+│   └── RELEASE_DEFINITION.md    # Release gates
+├── components/                  # Component RFCs
+│   ├── RFC-002-Input.md
+│   ├── RFC-003-Select.md
+│   └── RFC-004-Card.md
+└── platform/                    # Cross-cutting governance
+    └── README.md
+```
+
+## Status
+
+**Foundations v1.0 — FROZEN**
+
+Components build on foundations. Foundations do not change without v2.0 RFC.
+
+## Quick Links
+
+- [Foundations v1.0](foundations/FOUNDATIONS-v1.0.md)
+- [Compliance Matrix](COMPLIANCE_MATRIX.md)
+- [Component Template](foundations/COMPONENT_TEMPLATE.md)
+- [Semantic Color System](foundations/SEMANTIC_COLOR_SYSTEM.md)