Update editor generation pricing defaults

Unify and lower default mud-point prices across editor generation features and update related API/schema, docs and tests. Changes set gpt-image-2 to 1K=3 / 2K=5, audio1.0 to 5, and chirp-v5 to 12, and update server default JSON, frontend models/workflows, OpenAPI schema (require aspectRatio/imageSize/priceMudPoints for UI extraction), multiple UX docs (quick-edit viewport, UI extraction panel, pricing guidance) and accompanying tests to match the new defaults and validation rules.

docs/openapi/genarrative-external-v1.openapi.json

@@ -2838,13 +2838,33 @@
       "EditorUiDesignAssetExtractionRequest": {
         "type": "object",
         "required": [
-          "sourceImageSrc"
+          "sourceImageSrc",
+          "aspectRatio",
+          "imageSize",
+          "priceMudPoints"
         ],
         "properties": {
           "sourceImageSrc": {
             "type": "string",
             "description": "UI 设计图 Data URL。"
           },
+          "aspectRatio": {
+            "type": "string",
+            "const": "1:1",
+            "description": "UI 素材提取固定使用 1:1。"
+          },
+          "imageSize": {
+            "type": "string",
+            "enum": [
+              "1K",
+              "2K"
+            ],
+            "description": "框选数量少时使用 1K，超过阈值时使用 2K。"
+          },
+          "priceMudPoints": {
+            "type": "integer",
+            "minimum": 0
+          },
           "projectId": {
             "type": [
               "string",