Fix: Settings UI, Validation, and Tax Integrations

[khaira777]

Implementation Plan

1. Settings Phone Number Validation

Swap out the raw <input> used for the Business Phone with the existing PhoneInput component (or apply its E.164 validation logic) so it behaves identically to the Customer creation form.

2. Tax ID & Missing /tax Endpoint

• The Universal Approach: Rename references of "GSTIN" to a universal "Tax ID / Registration Number" in the UI.
• The Wiring: Build out a "Tax Settings" section in the Store tab that hooks into the currently unused GET/PUT /api/settings/tax backend endpoints. This will finally allow saving tax_registered, tax_scheme, and state_code.

3. Unicode Printer Toggle UI

Fix the flexbox utility classes on the "Printer supports Unicode" row. Wrap the label text and the toggle component in a proper flex items-center justify-between container so it aligns perfectly with the rest of the form.

4. POS Local Settings (Images & Mandatory Customer)

These are local device settings (saved instantly to localStorage via Zustand). To improve UX, add an immediate toast.success('Local POS setting saved') popup that fires the moment they are toggled, providing instant feedback.

5. KDS URL Clarification

In the KDS settings tab, add clear helper text below the standalone button: "The Kitchen Display System is hosted locally on port 3002. Devices on your Wi-Fi can connect by visiting http://[YOUR-LOCAL-IP]:3002".

6. Loyalty isDirty Popup Bug

The unsaved changes warning isn't clearing because the component's internal saved state isn't syncing up after a successful API call. Add a state update inside the saveLoyalty() success block to clear the dirty flag.

[khaira777]

🚀 Phase 2 Fixes & Discoveries (Post-Initial Audit)

During thorough testing, several additional edge cases were caught and fixed on this branch:

1. Tax ID Layout Shift (Fixed):

   • The settings grid layout was shifting weirdly when 'Tax Registered' was set to 'No'. Added a placeholder empty div to preserve the 2-column grid alignment.

2. Severe Loyalty Points Scale Bug (Fixed):

   • Discovered that earning points was scaling 1:1 with currency, but redemption required a 100:1 ratio. This made points effectively worthless to customers.
   • Fix: Multiplied the earned cashback by LOYALTY_REDEMPTION_RATE (100) on the backend so earning and redeeming use the same mathematical scale. Updated all integration tests to enforce this.

3. Database JSON Export Auth Error (Fixed):

   • Clicking 'Export Database' downloaded a JSON file with {"error":"Authentication required"} because the frontend fetch() call omitted the JWT token.
   • Fix: Refactored the export to use our api.get() instance which automatically handles auth interceptors.

4. Backup Management UI (Deferred to Feature: Backup Management & History UI #120):

   • Currently, creating a backup silently succeeds with a toast, leaving the user wondering where the file went.
   • Interim Fix: The toast now explicitly prints the absolute path of the generated .db file.
   • Permanent Fix: Deferred to Issue Feature: Backup Management & History UI #120, which will build a full backup history and restore UI.

5. Global Loyalty Setting & Overrides (Deferred to Enhancement: Refine Loyalty Program Onboarding and Labeling #81 / PR Enhancement: Refine Loyalty Program Onboarding #121):

   • Setting cb_percent individually for every single product is tedious.
   • Proposed redesign: Introduce a global_cashback_percent setting, and give each product 3 radio button options: 'No Cashback', 'Global Cashback', and 'Custom Cashback'. Furthermore, if loyalty is globally disabled, hide these product options completely to avoid confusion.
   • Action: Deferred to Issue Enhancement: Refine Loyalty Program Onboarding and Labeling #81 and PR Enhancement: Refine Loyalty Program Onboarding #121 to keep this PR tightly scoped.