feat(schema): templateProps + schemaRef + designGuide + blockStudio

Vorbereitung fuer dynamische Pagebuilder-Bloecke (nova feature/dynamic-pagebuilder-blocks):
- field-meta: Widget templateProps, meta.schemaRef {ref?, field required}
  (statische subFields / Sibling-Schema / FK-Schema fuer type:any-Felder)
- collection-meta: meta.designGuide (i18nText) als KI-Hinweis pro Collection
- collection-meta: viewHint.blockStudio {previewField, lint, renderer.file}
  (Spezial-View wie navigation/media, inkl. oneOf-Zweig)

schemas/config/collection-meta.schema.json

@@ -17,6 +17,9 @@
     "group": {
       "type": "string"
     },
+    "designGuide": {
+      "$ref": "defs.schema.json#/definitions/i18nText"
+    },
     "imageUrl": {
       "oneOf": [
         {
@@ -287,6 +290,30 @@
                   }
                 }
               }
+            },
+            "blockStudio": {
+              "type": "object",
+              "additionalProperties": false,
+              "properties": {
+                "previewField": {
+                  "type": "string"
+                },
+                "lint": {
+                  "type": "boolean"
+                },
+                "renderer": {
+                  "type": "object",
+                  "additionalProperties": false,
+                  "properties": {
+                    "file": {
+                      "type": "string"
+                    }
+                  },
+                  "required": [
+                    "file"
+                  ]
+                }
+              }
             }
           },
           "oneOf": [
@@ -299,6 +326,11 @@
               "required": [
                 "navigation"
               ]
+            },
+            {
+              "required": [
+                "blockStudio"
+              ]
             }
           ]
         }