fix: split report global keys into raw and computed across plugins

The `<plugin>-global-<property>` keys in `:report` output returned the resolved value with the built-in default substituted in, so external tooling could not distinguish a property that had been set globally to the default from one that had never been set. The bare keys for caddy, haproxy, and traefik global-only properties had the same shape. The `global-<property>` keys now hold the raw stored value and are empty when nothing has been set, and a new `computed-<property>` key holds the effective value used at runtime, falling back through the per-app value (where one exists), the global value, and the built-in default. The bare global-only keys for the three proxy plugins are removed in favor of the raw/computed pair. Closes #8631.

tests/unit/archive-security.bats

@@ -228,12 +228,24 @@ PY
   echo "output: $output"
   echo "status: $status"
   assert_success
+  assert_output ""
+
+  run /bin/bash -c "dokku git:report --global --git-computed-archive-max-size"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
   assert_output "1073741824"
 
   run /bin/bash -c "dokku git:report --global --git-global-archive-max-files"
   echo "output: $output"
   echo "status: $status"
   assert_success
+  assert_output ""
+
+  run /bin/bash -c "dokku git:report --global --git-computed-archive-max-files"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
   assert_output "10000"
 
   run /bin/bash -c "dokku git:set --global archive-max-size 2147483648"
@@ -244,6 +256,12 @@ PY
   assert_success
   assert_output "2147483648"
 
+  run /bin/bash -c "dokku git:report --global --git-computed-archive-max-size"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output "2147483648"
+
   run /bin/bash -c "dokku git:set --global archive-max-size"
   assert_success
 }