Extract OpenAPI schemas to separate file and move models to internal/model package

Split api/openapi.yaml schemas into api/schemas.yaml so structs can be
generated independently from the API server code. Models now generate
into internal/model/ via oapi-codegen, with the server referencing them
through import-mapping. Moved PtrTo helper to internal/utils and removed
storage.ReportSummary in favor of model.TestSummary.

api/config-models.yaml

@@ -1,5 +1,9 @@
-package: api
+package: model
 generate:
   models: true
-  embedded-spec: false
-output: internal/api/models.gen.go
+  embedded-spec: true
+output: internal/model/types.gen.go
+output-options:
+  skip-prune: true
+import-mapping:
+  ./schemas.yaml: "-"

api/config-server.yaml

@@ -1,5 +1,8 @@
 package: api
 generate:
   gin-server: true
+  models: true
   embedded-spec: true
 output: internal/api/server.gen.go
+import-mapping:
+  ./schemas.yaml: git.happydns.org/happyDeliver/internal/model