调整图片画布路由和画布数据模型

将图片画布入口改为 /editor/canvas

新增 editor_canvas 表并关联 editor_project 默认画布

更新 project API 响应中的 canvas 快照兼容层

统一图片画布侧栏列表项和图标按钮组件

同步前端测试、SpacetimeDB bindings、技术文档和 TRACKING 记录

server-rs/crates/spacetime-client/src/mapper/editor_project.rs

@@ -12,6 +12,7 @@ pub struct EditorProjectRecord {
     pub project_id: String,
     pub owner_user_id: String,
     pub title: String,
+    pub canvas: EditorCanvasRecord,
     pub viewport: EditorCanvasViewportRecord,
     pub layers: serde_json::Value,
     pub resources: Vec<EditorProjectResourceRecord>,
@@ -19,6 +20,17 @@ pub struct EditorProjectRecord {
     pub updated_at: String,
 }
 
+#[derive(Clone, Debug, PartialEq, serde::Serialize, serde::Deserialize)]
+pub struct EditorCanvasRecord {
+    pub canvas_id: String,
+    pub project_id: String,
+    pub title: String,
+    pub viewport: EditorCanvasViewportRecord,
+    pub layers: serde_json::Value,
+    pub created_at: String,
+    pub updated_at: String,
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 pub struct EditorProjectResourceRecord {
     pub resource_id: String,
@@ -178,19 +190,31 @@ pub(crate) fn map_editor_project_resource_procedure_result(
 fn map_editor_project_snapshot(
     snapshot: EditorProjectSnapshot,
 ) -> Result<EditorProjectRecord, SpacetimeClientError> {
-    let layers = serde_json::from_str(&snapshot.layers_json).map_err(|error| {
+    let layers: serde_json::Value =
+        serde_json::from_str(&snapshot.canvas.layers_json).map_err(|error| {
         SpacetimeClientError::validation_failed(format!("图片画布图层布局 JSON 无法解析：{error}"))
     })?;
+    let viewport = EditorCanvasViewportRecord {
+        x: snapshot.canvas.viewport.x,
+        y: snapshot.canvas.viewport.y,
+        scale: snapshot.canvas.viewport.scale,
+    };
+    let canvas = EditorCanvasRecord {
+        canvas_id: snapshot.canvas.canvas_id,
+        project_id: snapshot.canvas.project_id,
+        title: snapshot.canvas.title,
+        viewport: viewport.clone(),
+        layers: layers.clone(),
+        created_at: format_timestamp_micros(snapshot.canvas.created_at_micros),
+        updated_at: format_timestamp_micros(snapshot.canvas.updated_at_micros),
+    };
 
     Ok(EditorProjectRecord {
         project_id: snapshot.project_id,
         owner_user_id: snapshot.owner_user_id,
         title: snapshot.title,
-        viewport: EditorCanvasViewportRecord {
-            x: snapshot.viewport.x,
-            y: snapshot.viewport.y,
-            scale: snapshot.viewport.scale,
-        },
+        canvas,
+        viewport,
         layers,
         resources: snapshot
             .resources