fix(security): remove external Redis/MinIO/SMTP credentials from base appsettings.json

SEC-C-01 extended gap: 3 base appsettings.json files still referenced external
infrastructure (167.114.174.113) with Velik@2026 credentials and real SMTP
password — missed by the Wave 1 security fix which targeted DB credentials only.

Changes:
- iam-service-net/appsettings.json: Redis localhost (removed Velik@2026),
  SMTP localhost:1025 (removed Mailgun credentials)
- membership-service-net/appsettings.json: Redis localhost (removed Velik@2026)
- storage-service-net/appsettings.json: MinIO→localhost:9000 minioadmin/minioadmin,
  Redis→localhost (removed Velik@2026)

All production credentials (Redis, MinIO, SMTP) must be injected via
environment variables. Base appsettings.json targets docker-compose local stack.

CTO review finding: Redis__Password, MinIO:SecretKey, Email:SmtpPassword
must never appear in committed config files.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

services/iam-service-net/src/IamService.API/appsettings.json

@@ -33,9 +33,9 @@
         "DefaultConnection": "Host=localhost;Database=iam_service;Username=goodgo;Password=goodgo-local-2024"
     },
     "Redis": {
-        "Host": "167.114.174.113",
+        "Host": "localhost",
         "Port": 6379,
-        "Password": "Velik@2026",
+        "Password": "",
         "Database": 0,
         "ConnectTimeout": 5000,
         "SyncTimeout": 5000
@@ -48,10 +48,10 @@
         "RefreshTokenExpiryDays": 7
     },
     "Email": {
-        "SmtpServer": "smtp.mailgun.org",
-        "SmtpPort": 587,
-        "SmtpLogin": "admin@mail.goodgo.us",
-        "SmtpPassword": "a469e9333580ef5dbb141f01e33864ef-51afd2db-6c014754",
+        "SmtpServer": "localhost",
+        "SmtpPort": 1025,
+        "SmtpLogin": "",
+        "SmtpPassword": "",
         "SenderEmail": "verify@mail.goodgo.us",
         "SenderName": "GoodGo IAM Service",
         "BaseUrl": "http://localhost:5001"

services/membership-service-net/src/MembershipService.API/appsettings.json

@@ -33,9 +33,9 @@
         "DefaultConnection": "Host=localhost;Database=membership_service;Username=goodgo;Password=goodgo-local-2024"
     },
     "Redis": {
-        "Host": "167.114.174.113",
+        "Host": "localhost",
         "Port": 6379,
-        "Password": "Velik@2026",
+        "Password": "",
         "Database": 0,
         "ConnectTimeout": 5000,
         "SyncTimeout": 5000

services/storage-service-net/src/StorageService.API/appsettings.json

@@ -38,9 +38,9 @@
         "PreSignedUrlExpirationSeconds": 3600,
         "MaxFileSizeBytes": 104857600,
         "MinIO": {
-            "Endpoint": "167.114.174.113:9000",
+            "Endpoint": "localhost:9000",
             "AccessKey": "minioadmin",
-            "SecretKey": "Velik@2026",
+            "SecretKey": "minioadmin",
             "UseSSL": false,
             "Region": "us-east-1"
         },
@@ -52,9 +52,9 @@
         }
     },
     "Redis": {
-        "Host": "167.114.174.113",
+        "Host": "localhost",
         "Port": 6379,
-        "Password": "Velik@2026",
+        "Password": "",
         "Database": 0,
         "ConnectTimeout": 5000,
         "SyncTimeout": 5000