fix: correct fly.toml http_checks array format

- Change from nested [http_service.checks] object to [[http_service.http_checks]] array
- Fixes fly launch validation error: cannot unmarshal object into array
- Health check configuration now uses proper TOML array syntax

Author: h7ml

fly.toml

@@ -21,13 +21,12 @@ primary_region = 'hkg'
   processes = ['app']
 
   # Health check configuration
-  [http_service.checks]
-    [http_service.checks.health]
-      grace_period = "10s"
-      interval = "30s"
-      method = "GET"
-      timeout = "5s"
-      path = "/actuator/health"
+  [[http_service.http_checks]]
+    grace_period = "10s"
+    interval = "30s"
+    method = "GET"
+    timeout = "5s"
+    path = "/actuator/health"
 
 [[vm]]
   memory = '1gb'