feat(api): .NET 10 multi-tenant REST API

Full backend implementation:
- Multi-tenant cafe/restaurant management (menus, orders, tables, staff)
- POS order flow with ZarinPal and Snappfood payment integration
- OTP authentication via Kavenegar SMS
- QR digital menu with public discover/finder endpoints
- Customer loyalty, coupons, CRM
- PostgreSQL via EF Core, Redis for caching/sessions
- Background jobs, webhook handlers
- Full migration history

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/Meezi.Infrastructure/Discover/CafeDiscoverProfileSerializer.cs

@@ -0,0 +1,67 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Meezi.Core.Discover;
+
+namespace Meezi.Infrastructure.Discover;
+
+public static class CafeDiscoverProfileSerializer
+{
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        PropertyNameCaseInsensitive = true
+    };
+
+    public static CafeDiscoverProfile Deserialize(string? json)
+    {
+        if (string.IsNullOrWhiteSpace(json))
+            return new CafeDiscoverProfile();
+
+        try
+        {
+            var profile = JsonSerializer.Deserialize<CafeDiscoverProfile>(json, JsonOptions);
+            return Sanitize(profile ?? new CafeDiscoverProfile());
+        }
+        catch
+        {
+            return new CafeDiscoverProfile();
+        }
+    }
+
+    public static string Serialize(CafeDiscoverProfile profile) =>
+        JsonSerializer.Serialize(Sanitize(profile), JsonOptions);
+
+    public static CafeDiscoverProfile Sanitize(CafeDiscoverProfile input)
+    {
+        var p = new CafeDiscoverProfile
+        {
+            Size = NormalizeSingle(input.Size, CafeDiscoverProfileKeys.Sizes),
+            Floors = NormalizeSingle(input.Floors, CafeDiscoverProfileKeys.Floors),
+            NoiseLevel = NormalizeSingle(input.NoiseLevel, CafeDiscoverProfileKeys.NoiseLevels),
+            PriceTier = NormalizeSingle(input.PriceTier, CafeDiscoverProfileKeys.PriceTiers),
+            Themes = NormalizeList(input.Themes, CafeDiscoverProfileKeys.Themes),
+            Vibes = NormalizeList(input.Vibes, CafeDiscoverProfileKeys.Vibes),
+            Occasions = NormalizeList(input.Occasions, CafeDiscoverProfileKeys.Occasions),
+            SpaceFeatures = NormalizeList(input.SpaceFeatures, CafeDiscoverProfileKeys.SpaceFeatures)
+        };
+        return p;
+    }
+
+    private static string? NormalizeSingle(string? value, HashSet<string> allowed)
+    {
+        if (string.IsNullOrWhiteSpace(value)) return null;
+        var id = value.Trim().ToLowerInvariant();
+        return allowed.Contains(id) ? id : null;
+    }
+
+    private static List<string> NormalizeList(IEnumerable<string>? values, HashSet<string> allowed)
+    {
+        if (values is null) return [];
+        return values
+            .Select(v => v.Trim().ToLowerInvariant())
+            .Where(v => !string.IsNullOrEmpty(v) && allowed.Contains(v))
+            .Distinct()
+            .ToList();
+    }
+}

src/Meezi.Infrastructure/Discover/DiscoverBadgeMapping.cs

@@ -0,0 +1,33 @@
+using Meezi.Core.Discover;
+using Meezi.Core.Entities;
+using Meezi.Core.Enums;
+
+namespace Meezi.Infrastructure.Discover;
+
+public record CafeBadgeDto(string Key, string Label, string Icon);
+
+public static class DiscoverBadgeMapping
+{
+    public static IReadOnlyList<CafeBadgeDto> ToDtos(Cafe cafe, string lang = "fa")
+    {
+        if (cafe.PlanTier != PlanTier.Enterprise)
+            return [];
+
+        var keys = DiscoverBadgesSerializer.Deserialize(cafe.DiscoverBadgesJson);
+        var list = new List<CafeBadgeDto>();
+        foreach (var key in keys)
+        {
+            var def = CafeBadgeCatalog.Resolve(key);
+            if (def is null) continue;
+            var label = lang switch
+            {
+                "en" => def.LabelEn,
+                "ar" => def.LabelAr,
+                _ => def.LabelFa
+            };
+            list.Add(new CafeBadgeDto(def.Key, label, def.Icon));
+        }
+
+        return list;
+    }
+}

src/Meezi.Infrastructure/Discover/DiscoverBadgesSerializer.cs

@@ -0,0 +1,32 @@
+using System.Text.Json;
+using Meezi.Core.Discover;
+
+namespace Meezi.Infrastructure.Discover;
+
+public static class DiscoverBadgesSerializer
+{
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
+
+    public static IReadOnlyList<string> Deserialize(string? json)
+    {
+        if (string.IsNullOrWhiteSpace(json)) return [];
+        try
+        {
+            var list = JsonSerializer.Deserialize<List<string>>(json, JsonOptions);
+            return CafeBadgeCatalog.NormalizeKeys(list);
+        }
+        catch
+        {
+            return [];
+        }
+    }
+
+    public static string? Serialize(IEnumerable<string>? keys)
+    {
+        var normalized = CafeBadgeCatalog.NormalizeKeys(keys);
+        return normalized.Count == 0 ? null : JsonSerializer.Serialize(normalized, JsonOptions);
+    }
+}