feat(09-04): compile ordered Winter list schemas

- Typed columns, actions, default sort, search term, and page sizes
- Omitted sortable defaults to true and empty collections marshal as arrays
- Unknown keys, bad defaults, and path escape fail before routes are served

cabana/contracts.go

@@ -56,23 +56,6 @@ func (BackendUser) TableName() string { return "backend_users" }
 // Option is a dropdown choice shared with later schema plans.
 type Option = pact.Option
 
-// ListColumn is one compiled columns.yaml entry, in file order.
-type ListColumn struct {
-	Key        string `json:"key"`
-	Label      string `json:"label"`
-	Searchable bool   `json:"searchable"`
-	Sortable   bool   `json:"sortable"`
-	Type       string `json:"type,omitempty"`
-}
-
-// ListSchema is the boot-compiled list contract for one controller.
-type ListSchema struct {
-	Title          string       `json:"title,omitempty"`
-	RecordsPerPage int          `json:"recordsPerPage"`
-	ShowSearch     bool         `json:"showSearch"`
-	Columns        []ListColumn `json:"columns"`
-}
-
 // CompiledController is one admin controller after YAML compilation.
 type CompiledController struct {
 	PluginID   string