feat: configure Stripe environment variables for dev and k8s

- Add Stripe test API keys to dev.exs for local development
- Add placeholder Stripe env vars to k8s deployment to prevent startup crashes
- Includes secret_key, webhook_secret, and price_id configuration

config/dev.exs

@@ -211,3 +211,10 @@ config :towerops, :snmp_min_poll_interval, 60
 
 # Enable dev routes for dashboard and mailbox
 config :towerops, dev_routes: true
+
+# Stripe configuration for development
+config :towerops,
+  stripe_secret_key:
+    "sk_test_51T7zcQS77kvnTfgyu0DCQU2xVKzeaneVCueHaXV3jsIw6HAwGWWllEL3J8jGZOybHAtPyu6oYIiuvJHhReFtTycE00VrJYJ8Ao",
+  stripe_webhook_secret: "whsec_dev_fake_secret",
+  stripe_price_id: "price_dev_fake_id"

k8s/deployment.yaml

@@ -66,6 +66,12 @@ spec:
                 secretKeyRef:
                   name: towerops-secrets
                   key: CLOAK_KEY
+            - name: STRIPE_SECRET_KEY
+              value: "sk_test_fake_placeholder"
+            - name: STRIPE_WEBHOOK_SECRET
+              value: "whsec_fake_placeholder"
+            - name: STRIPE_PRICE_ID
+              value: "price_fake_placeholder"
           envFrom:
             - secretRef:
                 name: towerops-db
@@ -153,6 +159,12 @@ spec:
               value: "true"
             - name: DATABASE_SSL_VERIFY
               value: "false"
+            - name: STRIPE_SECRET_KEY
+              value: "sk_test_fake_placeholder"
+            - name: STRIPE_WEBHOOK_SECRET
+              value: "whsec_fake_placeholder"
+            - name: STRIPE_PRICE_ID
+              value: "price_fake_placeholder"
           envFrom:
             # Redis connection configured via towerops-redis secret
             - secretRef: