接入画板生成视频功能

新增画板底部生成视频入口、Lovart 风格面板、视频图层渲染与元数据展示。

接入 /api/editor/videos/generations 契约与后端 Ark/VectorEngine 视频任务链路。

统一编辑器生成类泥点配置，并补充 UI 设计图、参考图与生成面板结构测试。

更新编辑器技术方案、生成类面板方案和 Hermes 共享决策/踩坑记录。

server-rs/crates/platform-image/tests/vector_engine.rs

@@ -1,9 +1,11 @@
 use platform_image::vector_engine::{
     GPT_IMAGE_2_MODEL, ReferenceImage, VECTOR_ENGINE_PROVIDER, VectorEngineImageSettings,
     build_vector_engine_image_http_client, build_vector_engine_image_request_body,
-    build_vector_engine_image_request_body_with_model, create_vector_engine_image_edit,
-    create_vector_engine_image_generation,
+    build_vector_engine_image_request_body_with_model,
+    build_vector_engine_nanobanana_generate_content_request_body, create_vector_engine_image_edit,
+    create_vector_engine_image_generation, create_vector_engine_nanobanana_generate_content,
     vector_engine_images_edit_url, vector_engine_images_generation_url,
+    vector_engine_nanobanana_generate_content_url,
 };
 use std::{
     sync::{
@@ -69,6 +71,60 @@ fn vector_engine_request_body_can_use_nanobanana2_model() {
     assert_eq!(body["n"], 1);
 }
 
+#[test]
+fn vector_engine_request_body_can_use_nanobanana2_half_k() {
+    let body = build_vector_engine_image_request_body_with_model(
+        "gemini-3.1-flash-image-preview",
+        "生成图标 spritesheet",
+        None,
+        "512",
+        1,
+        &[],
+    );
+
+    assert_eq!(body["model"], "gemini-3.1-flash-image-preview");
+    assert_eq!(body["size"], "512");
+}
+
+#[test]
+fn nanobanana_generate_content_body_carries_aspect_ratio_and_image_size() {
+    let body = build_vector_engine_nanobanana_generate_content_request_body(
+        "生成角色图",
+        Some("文字、水印"),
+        "2:3",
+        "512",
+        &[],
+    );
+
+    assert_eq!(body["contents"][0]["role"], "user");
+    assert_eq!(
+        body["contents"][0]["parts"][0]["text"],
+        "生成角色图\n避免：文字、水印"
+    );
+    assert_eq!(body["generationConfig"]["responseModalities"][0], "IMAGE");
+    assert_eq!(
+        body["generationConfig"]["imageConfig"]["aspectRatio"],
+        "2:3"
+    );
+    assert_eq!(body["generationConfig"]["imageConfig"]["imageSize"], "512");
+    assert!(body.get("model").is_none());
+    assert!(body.get("n").is_none());
+}
+
+#[test]
+fn nanobanana_generate_content_url_uses_model_path() {
+    let settings = VectorEngineImageSettings {
+        base_url: "https://vector.example/v1".to_string(),
+        api_key: "test-key".to_string(),
+        request_timeout_ms: 1_000,
+    };
+
+    assert_eq!(
+        vector_engine_nanobanana_generate_content_url(&settings, "gemini-3.1-flash-image-preview"),
+        "https://vector.example/v1beta/models/gemini-3.1-flash-image-preview:generateContent"
+    );
+}
+
 #[tokio::test]
 async fn vector_engine_image_edit_retries_send_timeout_once_and_succeeds() {
     let listener = TcpListener::bind("127.0.0.1:0")
@@ -136,6 +192,73 @@ async fn vector_engine_image_edit_retries_send_timeout_once_and_succeeds() {
     server.abort();
 }
 
+#[tokio::test]
+async fn nanobanana_generate_content_posts_native_body_and_reads_inline_data() {
+    let listener = TcpListener::bind("127.0.0.1:0")
+        .await
+        .expect("mock server should bind");
+    let server_addr = listener
+        .local_addr()
+        .expect("mock server address should be readable");
+    let server = tokio::spawn(async move {
+        let Ok((mut stream, _)) = listener.accept().await else {
+            return;
+        };
+        let mut request = Vec::new();
+        let mut buffer = [0_u8; 4096];
+        loop {
+            let Ok(read) = stream.read(&mut buffer).await else {
+                return;
+            };
+            if read == 0 {
+                return;
+            }
+            request.extend_from_slice(&buffer[..read]);
+            if request.windows(4).any(|window| window == b"\r\n\r\n") {
+                break;
+            }
+        }
+        let request_text = String::from_utf8_lossy(request.as_slice());
+        assert!(
+            request_text.contains("/v1beta/models/gemini-3.1-flash-image-preview:generateContent")
+        );
+        assert!(request_text.contains("\"aspectRatio\":\"2:3\""));
+        assert!(request_text.contains("\"imageSize\":\"512\""));
+
+        let body = r#"{"candidates":[{"content":{"parts":[{"inlineData":{"mimeType":"image/png","data":"iVBORw0KGgpyZXN0"}}]}}]}"#;
+        let response = format!(
+            "HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: {}\r\n\r\n{}",
+            body.len(),
+            body
+        );
+        let _ = stream.write_all(response.as_bytes()).await;
+    });
+    let settings = VectorEngineImageSettings {
+        base_url: format!("http://{}", server_addr),
+        api_key: "test-key".to_string(),
+        request_timeout_ms: 1_000,
+    };
+    let client = build_vector_engine_image_http_client(&settings).expect("client should build");
+
+    let generated = create_vector_engine_nanobanana_generate_content(
+        &client,
+        &settings,
+        "gemini-3.1-flash-image-preview",
+        "生成角色图",
+        Some("文字、水印"),
+        "2:3",
+        "512",
+        &[],
+        "测试 nanobanana",
+    )
+    .await
+    .expect("nanobanana response should parse");
+
+    assert_eq!(generated.images.len(), 1);
+    assert_eq!(generated.images[0].mime_type, "image/png");
+    server.abort();
+}
+
 #[tokio::test]
 async fn vector_engine_image_generation_retries_upstream_502_once_and_succeeds() {
     let listener = TcpListener::bind("127.0.0.1:0")