feat(sms): bring-your-own-provider — cafés use their own SMS account

The platform no longer sells SMS. Each café saves its OWN Kavenegar API
key + sender line (new Cafes columns + migration) and campaigns are sent
and billed through that account.

Backend:
- GET/PUT /sms/settings (Manager/Owner; key echoed masked, verified
  against the provider before saving)
- campaign + balance use the café's credentials; SMS_NOT_CONFIGURED
  error when missing; plan-tier SMS gating removed everywhere
  (PlanLimitChecker, SmsMarketingService, billing status)
- platform Kavenegar config stays ONLY for login OTPs (env/DB)
- design-time DbContext factory so `dotnet ef migrations add` works
  without booting the host

Dashboard:
- SMS screen: provider-settings card, not-configured callout, campaign
  form disabled until configured; quota bar removed (usage stays as info)
- subscription screen + plan comparison no longer show SMS limits

Admin panel:
- Kavenegar/SMS section removed from integrations (request field now
  optional; stored OTP config untouched)
- SMS limit field removed from the plan editor
- nav label "درگاه و پیامک" → "درگاه پرداخت و AI"

fa/en/ar translations. 86 tests pass; all tsc clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Meezi.Admin.API/Services/PlatformIntegrationService.cs

@@ -107,23 +107,32 @@ public class PlatformIntegrationService : IPlatformIntegrationService
                 await SaveCredentialsAsync(meta.Prefix, gw.Id, gw.Credentials, ct);
         }
 
-        await UpsertAsync(KeyKavenegarEnabled, request.Kavenegar.IsEnabled ? "true" : "false", "integrations", "فعال کاوه‌نگار", ct);
-        await UpsertAsync(KeyKavenegarOtpTemplate, request.Kavenegar.OtpTemplate.Trim(), "integrations", "قالب OTP", ct);
-        if (!string.IsNullOrWhiteSpace(request.Kavenegar.ApiKey) && !IsMaskedPlaceholder(request.Kavenegar.ApiKey))
-            await UpsertAsync(KeyKavenegarApi, request.Kavenegar.ApiKey.Trim(), "integrations", "API Key کاوه‌نگار", ct);
-        if (!string.IsNullOrWhiteSpace(request.Kavenegar.SenderNumber))
-            await UpsertAsync(KeyKavenegarSender, request.Kavenegar.SenderNumber.Trim(), "integrations", "شماره فرستنده کاوه‌نگار", ct);
+        // SMS (Kavenegar) is no longer managed from the admin UI — marketing SMS is
+        // bring-your-own-provider per café, and the platform OTP credentials live in
+        // env/appsettings (or the previously-stored DB values, left untouched here).
+        if (request.Kavenegar is { } kavenegar)
+        {
+            await UpsertAsync(KeyKavenegarEnabled, kavenegar.IsEnabled ? "true" : "false", "integrations", "فعال کاوه‌نگار", ct);
+            await UpsertAsync(KeyKavenegarOtpTemplate, kavenegar.OtpTemplate.Trim(), "integrations", "قالب OTP", ct);
+            if (!string.IsNullOrWhiteSpace(kavenegar.ApiKey) && !IsMaskedPlaceholder(kavenegar.ApiKey))
+                await UpsertAsync(KeyKavenegarApi, kavenegar.ApiKey.Trim(), "integrations", "API Key کاوه‌نگار", ct);
+            if (!string.IsNullOrWhiteSpace(kavenegar.SenderNumber))
+                await UpsertAsync(KeyKavenegarSender, kavenegar.SenderNumber.Trim(), "integrations", "شماره فرستنده کاوه‌نگار", ct);
+        }
 
-        await UpsertAsync(PlatformIntegrationKeys.OpenAiEnabled, request.Ai.OpenAi.IsEnabled ? "true" : "false", "integrations", "فعال OpenAI", ct);
-        await UpsertAsync(PlatformIntegrationKeys.OpenAiModel, string.IsNullOrWhiteSpace(request.Ai.OpenAi.Model) ? "gpt-4o-mini" : request.Ai.OpenAi.Model.Trim(), "integrations", "مدل OpenAI", ct);
-        await UpsertAsync(PlatformIntegrationKeys.OpenAiCoffeeAdvisorEnabled, request.Ai.OpenAi.CoffeeAdvisorEnabled ? "true" : "false", "integrations", "مشاور قهوه OpenAI", ct);
-        if (!string.IsNullOrWhiteSpace(request.Ai.OpenAi.ApiKey) && !IsMaskedPlaceholder(request.Ai.OpenAi.ApiKey))
-            await UpsertAsync(PlatformIntegrationKeys.OpenAiApiKey, request.Ai.OpenAi.ApiKey.Trim(), "integrations", "API Key OpenAI", ct);
+        if (request.Ai is { } ai)
+        {
+            await UpsertAsync(PlatformIntegrationKeys.OpenAiEnabled, ai.OpenAi.IsEnabled ? "true" : "false", "integrations", "فعال OpenAI", ct);
+            await UpsertAsync(PlatformIntegrationKeys.OpenAiModel, string.IsNullOrWhiteSpace(ai.OpenAi.Model) ? "gpt-4o-mini" : ai.OpenAi.Model.Trim(), "integrations", "مدل OpenAI", ct);
+            await UpsertAsync(PlatformIntegrationKeys.OpenAiCoffeeAdvisorEnabled, ai.OpenAi.CoffeeAdvisorEnabled ? "true" : "false", "integrations", "مشاور قهوه OpenAI", ct);
+            if (!string.IsNullOrWhiteSpace(ai.OpenAi.ApiKey) && !IsMaskedPlaceholder(ai.OpenAi.ApiKey))
+                await UpsertAsync(PlatformIntegrationKeys.OpenAiApiKey, ai.OpenAi.ApiKey.Trim(), "integrations", "API Key OpenAI", ct);
 
-        await UpsertAsync(PlatformIntegrationKeys.MeshyEnabled, request.Ai.Meshy.IsEnabled ? "true" : "false", "integrations", "فعال Meshy", ct);
-        await UpsertAsync(PlatformIntegrationKeys.MeshyMenu3dEnabled, request.Ai.Meshy.Menu3dEnabled ? "true" : "false", "integrations", "ساخت ۳D منو با Meshy", ct);
-        if (!string.IsNullOrWhiteSpace(request.Ai.Meshy.ApiKey) && !IsMaskedPlaceholder(request.Ai.Meshy.ApiKey))
-            await UpsertAsync(PlatformIntegrationKeys.MeshyApiKey, request.Ai.Meshy.ApiKey.Trim(), "integrations", "API Key Meshy", ct);
+            await UpsertAsync(PlatformIntegrationKeys.MeshyEnabled, ai.Meshy.IsEnabled ? "true" : "false", "integrations", "فعال Meshy", ct);
+            await UpsertAsync(PlatformIntegrationKeys.MeshyMenu3dEnabled, ai.Meshy.Menu3dEnabled ? "true" : "false", "integrations", "ساخت ۳D منو با Meshy", ct);
+            if (!string.IsNullOrWhiteSpace(ai.Meshy.ApiKey) && !IsMaskedPlaceholder(ai.Meshy.ApiKey))
+                await UpsertAsync(PlatformIntegrationKeys.MeshyApiKey, ai.Meshy.ApiKey.Trim(), "integrations", "API Key Meshy", ct);
+        }
 
         await _db.SaveChangesAsync(ct);
         _catalog.InvalidateCache();