Step 4: Add admin UI page for pricing configuration

- Add pricing API functions to admin.ts
- Create admin pricing page with form and validation
- Add MANAGE_PRICING permission to auth context
- Add pricing to admin navigation
- Add translations for pricing page (en, ca, es)
- Update PageLayout and Header types for new page

frontend/locales/en/admin.json

@@ -109,5 +109,31 @@
       "clearFailed": "Failed to clear",
       "copyFailed": "Failed to copy"
     }
+  },
+  "pricing": {
+    "title": "Pricing Configuration",
+    "subtitle": "Configure premium pricing and trade amount limits",
+    "premiumSettings": "Premium Settings",
+    "premiumBuy": "Premium for BUY",
+    "premiumSell": "Premium for SELL",
+    "smallTradeThreshold": "Small Trade Threshold",
+    "smallTradeExtraPremium": "Extra Premium for Small Trades",
+    "tradeLimitsBuy": "Trade Amount Limits (BUY)",
+    "tradeLimitsSell": "Trade Amount Limits (SELL)",
+    "minAmount": "Minimum Amount",
+    "maxAmount": "Maximum Amount",
+    "save": "Save Changes",
+    "success": "Pricing configuration saved successfully",
+    "confirmSave": "Are you sure you want to save these pricing changes? This will affect all new trades immediately.",
+    "validation": {
+      "premiumRange": "Premium must be between -100% and 100%",
+      "positive": "Amount must be positive",
+      "minMaxBuy": "Minimum must be less than maximum for BUY",
+      "minMaxSell": "Minimum must be less than maximum for SELL"
+    },
+    "errors": {
+      "loadFailed": "Failed to load pricing configuration",
+      "saveFailed": "Failed to save pricing configuration"
+    }
   }
 }

frontend/locales/en/navigation.json

@@ -7,5 +7,6 @@
   "trades": "Trades",
   "availability": "Availability",
   "invites": "Invites",
-  "prices": "Prices"
+  "prices": "Prices",
+  "pricing": "Pricing"
 }