修复外部生成阶段上报与后处理降级

为 phase procedure 增加结构化 lease/fencing 拒绝结果并同步 typed bindings
仅对 Build、ConnectDropped、Timeout 重试一次，最终失败不回 pending
角色、图标和 UI 后处理最终失败时保留原图并以 completed warning 收口
同步 inline、队列轮询和刷新恢复 warning，保留 sliceWarning 契约
同步 external v1 OpenAPI、权威文档和 external editor skill
更新 BgFilter 服务地址

.codex/skills/genarrative-external-editor-api/SKILL.md

@@ -318,6 +318,14 @@ For image edit/redraw that should replace an existing canvas layer, pass `projec
 
 For sound effects and BGM, `assetFolderId` and `assetLabel` can write the generated audio to the account asset library, same as image/video generation.
 
+## Successful Responses with Warnings
+
+Character image generation (including character redraw through `kind: "character"`), icon spritesheet generation, and UI asset extraction can return HTTP 2xx with an optional structured `warning`. A 2xx response means the task completed, but it does not guarantee that every requested post-processed derivative exists.
+
+- Apply the returned `project` and media snapshots before interpreting optional derivatives: character responses use `resource` / `asset`, while icon spritesheet and UI extraction responses use `spritesheetResource` / `spritesheetAsset`. When `warning.code` is `postprocess-failed-source-preserved`, the saved provider source image is the authoritative main result. Character output has no transparent derivative; icon spritesheet and UI extraction output have neither a transparent spritesheet nor slices. Display `warning.reason` directly, and do not synthesize missing derivatives or restart generation.
+- `sliceWarning` is a separate condition used only when transparent spritesheet post-processing succeeded but automatic slicing failed. Keep `sliceWarning.reason` as the original diagnostic and continue using the complete transparent spritesheet; a UI may add context when displaying it, but must not rewrite the stored reason.
+- The service contract keeps `warning` and `sliceWarning` mutually exclusive. As defensive handling for a malformed response containing both, treat the general `warning` as authoritative and do not misclassify the source-preserved result as a slicing-only warning.
+
 ## Guardrails
 
 - Do not invent endpoints outside the OpenAPI, especially internal worker or runtime task-list routes.

.codex/skills/genarrative-external-editor-api/references/api-selection.md

@@ -78,6 +78,14 @@ Ask a follow-up only when two routes could both be correct and produce different
 
 All generation requests should be placed into both the current canvas and its same-name asset-library folder. For endpoints that support `assetLabel`, pass it. For UI extraction, use `spritesheetLabel`. For icon spritesheet, the folder is enough. For character animation, the endpoint does not return `asset`; after success call `POST /api/external/v1/editor/assets` using the first returned frame as `imageSrc`, the session `assetFolderId`, and `assetKind: "character-animation"`.
 
+## HTTP 2xx Warning Handling
+
+Character image generation (including character redraw through `kind: "character"`), icon spritesheet generation, and UI asset extraction may return HTTP 2xx while carrying a structured `warning`; completion does not imply that all post-processed derivatives exist.
+
+- Consume the returned `project` and media snapshots as authoritative: character responses use `resource` / `asset`, while icon spritesheet and UI extraction responses use `spritesheetResource` / `spritesheetAsset`. `warning.code: "postprocess-failed-source-preserved"` means the saved provider source is the main result. Character output has no transparent derivative, while icon spritesheet and UI extraction have no transparent spritesheet and no slices. Display `warning.reason` directly; do not construct missing assets or retry the provider generation from scratch.
+- `sliceWarning` is only for a transparent spritesheet that was created successfully but could not be split automatically. Use the complete transparent spritesheet and preserve `sliceWarning.reason` as the original diagnostic; it is not a post-processing/source-preserved warning.
+- The service contract keeps `warning` and `sliceWarning` mutually exclusive. If a malformed response contains both, prioritize the general `warning` over `sliceWarning` defensively.
+
 ## Reference Image Upload
 
 If the user provides a local file as a reference image, run upload before the generation request: