feat(codex-image): 封装 GPT Image 2 图片接口并收紧错误处理

- 新增 openai:image 路由、planner 与 finalize，内部通过 Codex responses image_generation tool 执行生图

- 补充 Codex OAuth/header 兼容、图片 success report 本地处理与相关前后端/集成测试

- 禁止 chat/completions 使用 gpt-image-2，图片接口限制 n=1，并移除 Provider 模型页的图片能力开关

crates/aether-admin/src/provider/models_write.rs

@@ -37,6 +37,7 @@ pub fn build_admin_provider_model_create_record(
     supports_function_calling: Option<bool>,
     supports_streaming: Option<bool>,
     supports_extended_thinking: Option<bool>,
+    supports_image_generation: Option<bool>,
     is_active: Option<bool>,
     config: Option<serde_json::Value>,
 ) -> Result<UpsertAdminProviderModelRecord, String> {
@@ -52,7 +53,7 @@ pub fn build_admin_provider_model_create_record(
         supports_function_calling,
         supports_streaming,
         supports_extended_thinking,
-        None,
+        supports_image_generation,
         is_active.unwrap_or(true),
         true,
         config,
@@ -72,6 +73,7 @@ pub fn build_admin_provider_model_update_record(
     supports_function_calling: Option<bool>,
     supports_streaming: Option<bool>,
     supports_extended_thinking: Option<bool>,
+    supports_image_generation: Option<bool>,
     is_active: bool,
     is_available: bool,
     config: Option<serde_json::Value>,
@@ -88,7 +90,7 @@ pub fn build_admin_provider_model_update_record(
         supports_function_calling,
         supports_streaming,
         supports_extended_thinking,
-        existing.supports_image_generation,
+        supports_image_generation,
         is_active,
         is_available,
         config,