Internationalize admin Dashboard page

[mighty840]

Description

The admin Dashboard page (packages/admin/src/pages/Dashboard.tsx) has all strings hardcoded in English with no i18n support. This includes section headings, labels, chart titles, and empty state messages.

Hardcoded Strings

• "Dashboard", "Overview", "Analytics"
• "Recent Orders", "View All"
• "Top Selling Items", "View Menu"
• "No orders yet.", "sold"
• Chart titles: "Revenue Trend", "Daily Orders", "Order Types", "Order Status", "Orders by Hour of Day", "Revenue by Category"

Steps

1. Set up i18n in the admin package if not already configured
2. Add translation keys under a dashboard namespace
3. Replace all hardcoded strings with t() calls
4. Add translations for all supported languages (en, es, fr, de, it, pt)

Effort

M — many strings to extract, but each change is mechanical