完成 SFX V2 T5 正式生成链路

接通 Luna 英文化、ElevenLabs 单次生成、MP3 校验、OSS 与权威元数据写回
演进站内和 External v1 契约、幂等参数、详情重绘与 Agent 音效模型
新增 ElevenLabs 动态定价键及历史定价快照兼容
同步 OpenAPI、外部 Agent Skill、共享计划与决策记录

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

@@ -4449,25 +4449,41 @@
       "EditorSoundEffectGenerationRequest": {
         "type": "object",
         "required": [
-          "prompt",
-          "duration"
+          "prompt"
         ],
         "properties": {
           "prompt": {
             "type": "string",
-            "minLength": 1
+            "minLength": 1,
+            "maxLength": 2048,
+            "description": "用户原始语言音效描述。服务端只删除首尾 Unicode White_Space，并按 Unicode code point 校验 1-2048。"
           },
           "model": {
             "type": [
               "string",
               "null"
             ],
-            "default": "audio1.0"
+            "default": "eleven_text_to_sound_v2",
+            "description": "省略、null、空串、纯 Unicode White_Space 或首尾空白包围的 eleven_text_to_sound_v2 均 canonicalize 为 eleven_text_to_sound_v2；audio1.0 和其它非空值返回 400。"
           },
           "duration": {
-            "type": "integer",
-            "minimum": 2,
-            "maximum": 10
+            "anyOf": [
+              {
+                "type": "number",
+                "minimum": 0.5,
+                "maximum": 30
+              },
+              {
+                "type": "null"
+              }
+            ],
+            "default": null,
+            "description": "null 或省略表示自动时长；有限数值表示手动时长。服务端不按 UI 0.1 秒步进取整。"
+          },
+          "loop": {
+            "type": "boolean",
+            "default": false,
+            "description": "独立 Loop 参数；服务端不从 Prompt 推断、同步或校验。"
           },
           "projectId": {
             "type": [
@@ -4629,6 +4645,22 @@
               "background-music"
             ]
           },
+          "durationSeconds": {
+            "type": [
+              "number",
+              "null"
+            ],
+            "exclusiveMinimum": 0,
+            "maximum": 600,
+            "description": "SFX V2 为 MP3 探测所得实际时长；不是请求时长。BGM 或历史结果可省略。"
+          },
+          "loop": {
+            "type": [
+              "boolean",
+              "null"
+            ],
+            "description": "SFX V2 返回冻结并发送给 provider 的 Loop；BGM 或历史结果可省略。"
+          },
           "project": {
             "anyOf": [
               {