docs: Component Architecture - Tiers, Inheritance, Minimalism

- Add Component Architecture (chapter 8):
  - Tier 1 Canonical: Button, Input, Select, Card, Modal, Navigation,
    Table, Data Grid, Search, Map Panel (10 components)
  - Tier 2 Derived: Badge, Alert, Toast, Tooltip, Accordion, Tabs,
    Breadcrumb, Pagination, Empty State, Skeleton (10 components)
  - Tier 3 Domain: KPI Card, Map Overlay Panel, Layer Selector,
    Mission Status, Dataset Card, Geospatial Inspector, Asset Summary,
    Coordinate Picker, Timeline Panel (9 components)
  - Component Inheritance: visual hierarchy showing parent-child
    relationships (Button to Icon Button to Split Button, etc.)
  - New Component Rule: 4-step checklist before creating anything new
  - Principle: system shall be minimal, not maximal

- Restructure component numbering: 8.3.x for specifications
- Update table of contents with new structure

Rationale: Components before colors (component structure drives color
usage). Tiers prevent bloat. Inheritance prevents duplication.
Minimalism principle reduces complexity.

docs/design/LANDVEX_DESIGN_SPECIFICATION.md

@@ -54,7 +54,11 @@ See `TOKEN_PHILOSOPHY.md` for the complete token governance rules.
 7. [Iconography](#7-iconography)
 
 ### PART C — COMPONENTS
-8. [Components](#8-components)
+8. [Component Architecture](#8-component-architecture)
+   - 8.0 Component Tiers (Tier 1/2/3)
+   - 8.1 Component Inheritance
+   - 8.2 New Component Rule
+   - 8.3 Component Specifications
 9. [Maps & Geospatial Layer](#9-maps--geospatial-layer)
 10. [Accessibility](#10-accessibility)
 11. [Responsive Behavior](#11-responsive-behavior)
@@ -513,13 +517,110 @@ Dedicated palette for geospatial visualization:
 
 ## PART C — COMPONENTS
 
-## 8. Components
+## 8. Component Architecture
 
-> **Status:** ⏳ Ej påbörjad
+> **Status:** ✅ Specified
+> **Principle:** The system shall be minimal, not maximal. Extend only when a recurring need cannot be solved with existing components.
+
+### 8.0 Component Tiers
+
+#### Tier 1 — Canonical Components
+
+These define the entire design system. If these are correct, everything else follows.
+
+| Component | Purpose | Inherits From |
+|-----------|---------|---------------|
+| **Button** | Primary action trigger | — |
+| **Input** | Text entry, form fields | — |
+| **Select** | Choice from predefined options | — |
+| **Card** | Content container, elevation | — |
+| **Modal** | Overlay dialog, focus trap | — |
+| **Navigation** | Primary wayfinding | — |
+| **Table** | Tabular data display | — |
+| **Data Grid** | Complex data with sorting/filtering | Table |
+| **Search** | Find and filter | Input |
+| **Map Panel** | Geospatial information overlay | Card |
+
+#### Tier 2 — Derived Components
+
+These build primarily on Tier 1. They introduce no new visual rules.
+
+| Component | Purpose | Inherits From |
+|-----------|---------|---------------|
+| **Badge** | Status indicator | — |
+| **Alert** | Contextual message | Card |
+| **Toast** | Transient notification | Card |
+| **Tooltip** | Contextual help | — |
+| **Accordion** | Collapsible content sections | Card |
+| **Tabs** | Content switching | — |
+| **Breadcrumb** | Location indicator | — |
+| **Pagination** | Page navigation | Button |
+| **Empty State** | No content placeholder | Card |
+| **Skeleton** | Loading placeholder | — |
+
+#### Tier 3 — Domain Components
+
+Landvex-specific. They explicitly build on Tier 1 and Tier 2. No new visual rules.
+
+| Component | Purpose | Inherits From |
+|-----------|---------|---------------|
+| **KPI Card** | Key metric display | Card |
+| **Map Overlay Panel** | Geospatial tool panel | Map Panel |
+| **Layer Selector** | Map layer toggle | Select |
+| **Mission Status** | Mission state indicator | Badge |
+| **Dataset Card** | Data source preview | Card |
+| **Geospatial Inspector** | Feature detail view | Card |
+| **Asset Summary** | Asset overview panel | Card |
+| **Coordinate Picker** | Lat/long input | Input |
+| **Timeline Panel** | Temporal data view | Card |
+
+### 8.1 Component Inheritance
+
+Components inherit visual properties, states, and behavior from their parent. Child components may add but never override parent rules.
+
+```
+Button
+├── Icon Button (adds icon, keeps all Button states)
+├── Split Button (adds dropdown, keeps primary action)
+└── Floating Action Button (fixed position, keeps Button behavior)
+
+Card
+├── KPI Card (adds metric layout, keeps Card elevation)
+├── Dataset Card (adds metadata, keeps Card structure)
+└── Mission Card (adds status, keeps Card padding)
+
+Table
+├── Data Grid (adds sorting/filtering, keeps Table structure)
+├── Inspection Grid (adds checkboxes, keeps Data Grid behavior)
+└── Asset Grid (adds thumbnails, keeps Data Grid behavior)
+```
+
+### 8.2 New Component Rule
+
+**New component is the last resort.**
+
+Before a new component may be created, verify:
+
+1. **Can an existing component be used?**
+2. **Can a variant be created?**
+3. **Can a modifier be used?**
+4. **Can a new state solve the problem?**
+
+Only then may a new component be defined.
+
+**New components must:**
+- Inherit from an existing component when possible
+- Follow the three-tier hierarchy
+- Include full specification (states, ARIA, keyboard, touch, animation, acceptance criteria)
+- Pass Design Review Gate
+
+---
+
+## 8.3 Component Specifications
 
 > **Princip:** Varje komponent har en egen specifikation med states, ARIA, keyboard, touch, animation och acceptance criteria.
 
-### 8.1 Button
+### 8.3.1 Button
 
 **States:**
 - Default
@@ -562,33 +663,33 @@ Dedicated palette for geospatial visualization:
 - [ ] Disabled state is not focusable
 - [ ] Touch target meets 44px minimum
 
-### 8.2 Input / Text Field
+### 8.3.2 Input / Text Field
 
-### 8.3 Select / Dropdown
+### 8.3.3 Select / Dropdown
 
-### 8.4 Checkbox
+### 8.3.4 Checkbox
 
-### 8.5 Radio Button
+### 8.3.5 Radio Button
 
-### 8.6 Toggle / Switch
+### 8.3.6 Toggle / Switch
 
-### 8.7 Card
+### 8.3.7 Card
 
-### 8.8 Modal / Dialog
+### 8.3.8 Modal / Dialog
 
-### 8.9 Toast / Notification
+### 8.3.9 Toast / Notification
 
-### 8.10 Tooltip
+### 8.3.10 Tooltip
 
-### 8.11 Data Table
+### 8.3.11 Data Table
 
-### 8.12 Tabs
+### 8.3.12 Tabs
 
-### 8.13 Navigation
+### 8.3.13 Navigation
 
-### 8.14 Sidebar
+### 8.3.14 Sidebar
 
-### 8.15 Map Overlay
+### 8.3.15 Map Overlay
 
 ---