feat: implement reactive store for active order with Svelte 5

CLAUDE.md

@@ -257,6 +257,16 @@ Dual testing setup with different environments:
 - Snippet syntax for slot-like components
 - Compile errors if mixing old and new syntax
 
+### UI Components & Styling
+
+- **Skeleton UI Components**: Use Skeleton Labs components for consistent UI
+  - Reference: https://www.skeleton.dev/llms-svelte.txt (use this for LLM context)
+  - Always use Skeleton components with **Tailwind CSS classes only**
+  - **NO inline styles** - use Tailwind utilities for all styling
+  - **NO `<style>` blocks** unless absolutely necessary for complex animations/behavior
+  - Use Tailwind's utility classes for responsive design and state variants
+  - Leverage Skeleton's pre-built components (buttons, cards, modals, etc.) instead of creating custom ones
+
 ## Important Notes
 
 - **Package Manager**: Always use `pnpm` (never npm or yarn)

docs/ROADMAP.md

@@ -22,8 +22,8 @@ Quick checklist of all issues in planned order.
 ## Phase 1
 
 - [x] **1.1** - TypeScript Interfaces for Business Domain (TDD) (#GH-10)
-- [ ] **1.2** - Calculate Margins and Totals Logic (TDD) (#GH-11)
-- [ ] **1.3** - Svelte Store for Active Order (Svelte 5 Runes - TDD) (#GH-12)
+- [x] **1.2** - Calculate Margins and Totals Logic (TDD) (#GH-11)
+- [x] **1.3** - Svelte Store for Active Order (Svelte 5 Runes - TDD) (#GH-12)
 - [ ] **1.4** - Product Form Component Tests (TDD) (#GH-13-test)
 - [ ] **1.4a** - Product Form Component (#GH-13)
 - [ ] **1.5** - Product Grid Component Tests (POS-style - TDD) (#GH-14-test)

src/lib/index.ts

@@ -10,3 +10,4 @@ export {
 	DB_NAME
 } from './db/database';
 export { config } from './config';
+export { createOrderStore, getOrderStore } from './stores/order.svelte';