fix(tree): stabilize filetree mindmap switching

Open filetree mindmap assets inside the primary document pane so the sidebar root is not rebuilt during rapid mindmap/page switching.

Keep filetree active rows on doc:<documentId> and asset:<mindmapId>, shorten generated mindmap filenames, and preserve legacy index rows only as compatibility input.

Add task438-task445 browser smokes and close the 4-27/4-38/4-39/4-40 tree-domain bug records.

wolai-frontend/convex/sidebar.ts

@@ -78,6 +78,8 @@ function extractMindmapImageAssetIdsFromData(input: unknown): string[] {
 
 function toMindmapAsset(row: MindmapRow, workspaceId: string) {
   const isLegacy = row.mindmap_id.startsWith("legacy-");
+  const suffix = row.mindmap_id.match(/(\d{4,})$/)?.[1]?.slice(-4) ?? row.mindmap_id.replace(/^mindmap[_-]?/i, "").slice(-6);
+  const fileName = suffix ? `思维导图-${suffix}.json` : "思维导图.json";
   return {
     id: row.mindmap_id,
     workspace_id: row.workspace_id ?? workspaceId,
@@ -87,7 +89,7 @@ function toMindmapAsset(row: MindmapRow, workspaceId: string) {
     thumbnail_url: null,
     bucket: null,
     storage_path: null,
-    file_name: isLegacy ? "mindmap.json" : `mindmap-${row.mindmap_id}.json`,
+    file_name: isLegacy ? "思维导图.json" : fileName,
     file_size: null,
     mime_type: "application/json",
     ocr_payload: undefined,

wolai-frontend/src/lib/sidebar-data.ts

@@ -191,6 +191,8 @@ export function extractMindmapImageAssetIdsFromData(input: unknown): string[] {
 
 function toMindmapAsset(row: MindmapRow, workspaceId: string): MediaAsset {
   const isLegacy = row.mindmap_id.startsWith("legacy-");
+  const suffix = row.mindmap_id.match(/(\d{4,})$/)?.[1]?.slice(-4) ?? row.mindmap_id.replace(/^mindmap[_-]?/i, "").slice(-6);
+  const fileName = suffix ? `思维导图-${suffix}.json` : "思维导图.json";
   return {
     id: row.mindmap_id,
     workspace_id: row.workspace_id ?? workspaceId,
@@ -200,7 +202,7 @@ function toMindmapAsset(row: MindmapRow, workspaceId: string): MediaAsset {
     thumbnail_url: null,
     bucket: null,
     storage_path: null,
-    file_name: isLegacy ? "mindmap.json" : `mindmap-${row.mindmap_id}.json`,
+    file_name: isLegacy ? "思维导图.json" : fileName,
     file_size: null,
     mime_type: "application/json",
     ocr_payload: undefined,