fix: prevent crash when opening notes

Move setActiveTabPath after tab content is loaded to prevent Editor's
useEffect from firing before the tab exists in the tabs array. Add
try/catch around editor.replaceBlocks for defensive error handling.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/Editor.tsx

@@ -180,18 +180,27 @@ export const Editor = memo(function Editor({
     const tab = tabs.find(t => t.entry.path === activeTabPath)
     if (!tab) return
 
-    if (cache.has(activeTabPath)) {
-      // Instant switch — use cached blocks
-      editor.replaceBlocks(editor.document, cache.get(activeTabPath)!)
-    } else {
-      // First open — parse markdown
-      const [, body] = splitFrontmatter(tab.content)
-      const preprocessed = preProcessWikilinks(body)
-      editor.tryParseMarkdownToBlocks(preprocessed).then(blocks => {
-        const withWikilinks = injectWikilinks(blocks)
-        editor.replaceBlocks(editor.document, withWikilinks)
-        cache.set(activeTabPath, withWikilinks)
-      })
+    try {
+      if (cache.has(activeTabPath)) {
+        // Instant switch — use cached blocks
+        editor.replaceBlocks(editor.document, cache.get(activeTabPath)!)
+      } else {
+        // First open — parse markdown
+        const [, body] = splitFrontmatter(tab.content)
+        const preprocessed = preProcessWikilinks(body)
+        editor.tryParseMarkdownToBlocks(preprocessed).then(blocks => {
+          const withWikilinks = injectWikilinks(blocks)
+          try {
+            editor.replaceBlocks(editor.document, withWikilinks)
+          } catch (err) {
+            console.error('Failed to replace blocks:', err)
+            return
+          }
+          cache.set(activeTabPath, withWikilinks)
+        })
+      }
+    } catch (err) {
+      console.error('Failed to swap editor content:', err)
     }
   }, [activeTabPath, tabs, editor])
 

src/hooks/useNoteActions.ts

@@ -111,10 +111,7 @@ export function useNoteActions(
       return
     }
 
-    // Set active immediately for instant visual feedback
-    setActiveTabPath(entry.path)
-
-    // Load content async
+    // Load content async, then add tab and set active together
     try {
       const content = isTauri()
         ? await invoke<string>('get_note_content', { path: entry.path })
@@ -123,12 +120,14 @@ export function useNoteActions(
         if (prev.some((t) => t.entry.path === entry.path)) return prev
         return [...prev, { entry, content }]
       })
+      setActiveTabPath(entry.path)
     } catch (err) {
       console.warn('Failed to load note content:', err)
       setTabs((prev) => {
         if (prev.some((t) => t.entry.path === entry.path)) return prev
         return [...prev, { entry, content: '' }]
       })
+      setActiveTabPath(entry.path)
     }
   }, [])