feat(10.1-01): serve controller JS/CSS and run registered toolbar actions

- boardwalk exports ContentType and SetSecurityHeaders
- pact.AdminClientAssets files are read and hashed at boot and served by exact
  key under {prefix}/assets/{vendor}/{plugin}/ with nosniff, CSP, CORP,
  no-cache and an ETag; a miss falls through to the SPA
- list and form schemas carry assets URLs with a ?v= hash
- toolbar.buttons resolves create, delete and registered actions after decode;
  toolbarActions is permission-filtered per admin
- POST .../toolbar/{action} behind requireAjax and action permissions

modules/cabana/list_schema.go

@@ -125,7 +125,7 @@ func compileList(pluginID string, ctl pact.AdminController, fsys fs.FS) (*ListSc
 			return nil, bootErr(pluginID, ctl.ID(), cfgPath, fmt.Errorf("unsupported search mode %s", mode))
 		}
 	}
-	buttons, err := compileToolbarButtons(doc.Toolbar, doc.ShowCheckboxes)
+	buttons, toolbarActions, err := compileToolbarButtons(ctl, doc.Toolbar, doc.ShowCheckboxes)
 	if err != nil {
 		return nil, bootErr(pluginID, ctl.ID(), cfgPath, err)
 	}
@@ -171,6 +171,7 @@ func compileList(pluginID string, ctl pact.AdminController, fsys fs.FS) (*ListSc
 		SearchPrompt:     prompt,
 		DefaultSort:      sort,
 		ToolbarButtons:   buttons,
+		ToolbarActions:   toolbarActions,
 		Columns:          columns,
 		Filters:          filters,
 		RowActions:       rowActions,
@@ -278,16 +279,15 @@ func compilePageOptions(recordsPerPage int, declared []int) ([]int, error) {
 	return options, nil
 }
 
-// toolbarButtons is the declarative toolbar.buttons list (D-14): built-in
-// actions in display order. A scalar (Winter's partial name) is rejected
-// with a pointer at the list syntax.
+// toolbarButtons is the declarative toolbar.buttons list (D-14, D-12):
+// action names in display order. The built-in create and delete sit next to
+// names the controller registers through pact.HasAdminActions; decode has no
+// controller, so membership is resolved in compileToolbarButtons. A scalar
+// (Winter's partial name) is rejected with a pointer at the list syntax.
 type toolbarButtons struct {
 	items []string
 }
 
-// toolbarActions are the built-in toolbar actions; custom actions are Phase 10.1.
-var toolbarActions = map[string]struct{}{"create": {}, "delete": {}}
-
 func (b *toolbarButtons) UnmarshalYAML(node ast.Node) error {
 	node = unwrapNode(node)
 	switch n := node.(type) {
@@ -301,10 +301,7 @@ func (b *toolbarButtons) UnmarshalYAML(node ast.Node) error {
 		for _, item := range values {
 			action, err := nodeString(unwrapNode(item))
 			if err != nil {
-				return fmt.Errorf("toolbar.buttons entries must be action names (create, delete)")
-			}
-			if _, ok := toolbarActions[action]; !ok {
-				return fmt.Errorf("toolbar.buttons: unsupported action %s (want create or delete)", action)
+				return fmt.Errorf("toolbar.buttons entries must be action names")
 			}
 			if _, dup := seen[action]; dup {
 				return fmt.Errorf("toolbar.buttons: duplicate action %s", action)
@@ -315,21 +312,43 @@ func (b *toolbarButtons) UnmarshalYAML(node ast.Node) error {
 		b.items = items
 		return nil
 	default:
-		return fmt.Errorf("toolbar.buttons must be a list of actions (create, delete); the Winter partial %q is not supported", nodeText(node))
+		return fmt.Errorf("toolbar.buttons must be a list of actions (create, delete or registered actions); the Winter partial %q is not supported", nodeText(node))
 	}
 }
 
-func compileToolbarButtons(toolbar *listToolbar, showCheckboxes bool) ([]string, error) {
+// compileToolbarButtons resolves every toolbar.buttons name against the
+// built-in create and delete and the controller's registered actions: the one
+// action namespace widgets use too. It returns the names in declared order and
+// the registered entries with their (source) labels.
+func compileToolbarButtons(ctl pact.AdminController, toolbar *listToolbar, showCheckboxes bool) ([]string, []ToolbarAction, error) {
 	if toolbar == nil || len(toolbar.Buttons.items) == 0 {
-		return []string{}, nil
+		return []string{}, []ToolbarAction{}, nil
 	}
-	out := append([]string(nil), toolbar.Buttons.items...)
-	for _, action := range out {
-		if action == "delete" && !showCheckboxes {
-			return nil, fmt.Errorf("toolbar.buttons: delete needs showCheckboxes: true")
+	registered := map[string]pact.AdminAction{}
+	if src, ok := ctl.(pact.HasAdminActions); ok && src != nil {
+		for _, action := range src.AdminActions() {
+			registered[action.Name] = action
 		}
 	}
-	return out, nil
+	out := append([]string(nil), toolbar.Buttons.items...)
+	custom := []ToolbarAction{}
+	for _, name := range out {
+		if builtinToolbarActions[name] {
+			if name == "delete" && !showCheckboxes {
+				return nil, nil, fmt.Errorf("toolbar.buttons: delete needs showCheckboxes: true")
+			}
+			continue
+		}
+		action, ok := registered[name]
+		if !ok {
+			return nil, nil, fmt.Errorf("toolbar.buttons: unsupported action %s (want create, delete or an action the controller registers)", name)
+		}
+		if strings.TrimSpace(action.Label) == "" {
+			return nil, nil, fmt.Errorf("toolbar.buttons: action %s needs a label", name)
+		}
+		custom = append(custom, ToolbarAction{Name: name, Label: action.Label})
+	}
+	return out, custom, nil
 }
 
 func compileDefaultSort(doc *listSortDocument, columns []ListColumn) (*ListSort, error) {
@@ -433,6 +452,15 @@ func (s *ListSchema) Localize(ctx context.Context, tr *phrasebook.Translator) (*
 	out.SearchPrompt = translateKey(ctx, tr, s.SearchPrompt)
 	out.PerPageOptions = append([]int(nil), s.PerPageOptions...)
 	out.ToolbarButtons = append([]string(nil), s.ToolbarButtons...)
+	out.ToolbarActions = make([]ToolbarAction, len(s.ToolbarActions))
+	for i, action := range s.ToolbarActions {
+		action.Label = translateKey(ctx, tr, action.Label)
+		out.ToolbarActions[i] = action
+	}
+	out.Assets = ControllerAssets{
+		Scripts: append([]string{}, s.Assets.Scripts...),
+		Styles:  append([]string{}, s.Assets.Styles...),
+	}
 	if s.DefaultSort != nil {
 		sort := *s.DefaultSort
 		out.DefaultSort = &sort