Switch to VectorEngine gpt-image-2 and edits

Replace uses of the legacy `gpt-image-2-all` model with `gpt-image-2` and standardize image workflows: no-reference generation uses POST /v1/images/generations, any-reference flows use POST /v1/images/edits with multipart `image` parts. Update SKILLs, generation scripts, decision logs, and docs to reflect the contract change and edits-vs-generations guidance. Apply corresponding changes across backend (api-server match3d/puzzle modules, openai image adapter, mappers, telemetry, spacetime client/module), frontend components and services (Match3D, Puzzle, CreativeImageInputPanel, runtime shells), and add new spritesheet/parser files and tests. Also add media/logo.png. These changes align repository code and documentation with the VectorEngine image API contract and update generation/upload handling (green-screen -> alpha processing, spritesheet handling, and related tests).

server-rs/crates/api-server/src/prompt/puzzle/draft.rs

@@ -40,9 +40,11 @@ pub(crate) fn resolve_puzzle_draft_cover_prompt(
 pub(crate) fn resolve_puzzle_level_image_prompt(
     explicit_prompt: Option<&str>,
     level_picture_description: &str,
+    draft_summary: &str,
 ) -> String {
     normalize_prompt_part(explicit_prompt)
         .or_else(|| normalize_prompt_part(Some(level_picture_description)))
+        .or_else(|| normalize_prompt_part(Some(draft_summary)))
         .unwrap_or_default()
         .to_string()
 }
@@ -76,8 +78,15 @@ mod tests {
 
     #[test]
     fn level_image_prompt_falls_back_to_level_description() {
-        let prompt = resolve_puzzle_level_image_prompt(Some("   "), "关卡画面描述");
+        let prompt = resolve_puzzle_level_image_prompt(Some("   "), "关卡画面描述", "作品简介");
 
         assert_eq!(prompt, "关卡画面描述");
     }
+
+    #[test]
+    fn level_image_prompt_falls_back_to_draft_summary_like_initial_cover() {
+        let prompt = resolve_puzzle_level_image_prompt(Some("   "), "   ", "作品简介");
+
+        assert_eq!(prompt, "作品简介");
+    }
 }