feat: improve dashboard navigation to files by focusing parent directory and syncing active state

- Extract getParentDirectoryPath helper to get parent directory from file path
- Extract syncActiveFileTreeItem helper to manage active tree item highlighting
- Update dashboard file navigation to focus parent directory with expansion instead of file itself
- Manually sync active state after navigation to ensure file is highlighted in tree
- Refactor openFile to use new syncActiveFileTreeItem helper

frontend/app.js

@@ -2410,6 +2410,26 @@
     scrollTreeItemIntoView(lastTargetItem, options && options.alignToTop);
   }
 
+  function getParentDirectoryPath(filePath) {
+    if (!filePath) return "";
+    const segments = filePath.split("/").filter(Boolean);
+    if (segments.length <= 1) return "";
+    segments.pop();
+    return segments.join("/");
+  }
+
+  function syncActiveFileTreeItem(vaultName, filePath) {
+    document.querySelectorAll(".tree-item.active").forEach((el) => el.classList.remove("active"));
+    if (!vaultName || !filePath) return;
+    const selector = `.tree-item[data-vault="${CSS.escape(vaultName)}"][data-path="${CSS.escape(filePath)}"]`;
+    try {
+      const active = document.querySelector(selector);
+      if (active) active.classList.add("active");
+    } catch (e) {
+      /* selector might fail on special chars */
+    }
+  }
+
   async function loadDirectory(vaultName, dirPath, container) {
     // Only show the loading spinner if the container is currently empty
     const isEmpty = container.children.length === 0;
@@ -2631,7 +2651,8 @@
             await focusPathInSidebar(entry.vault, entry.path, { alignToTop: true, expandTarget: true });
           } else {
             await openFile(entry.vault, entry.path);
-            await focusPathInSidebar(entry.vault, entry.path, { alignToTop: false });
+            await focusPathInSidebar(entry.vault, getParentDirectoryPath(entry.path), { alignToTop: true, expandTarget: true });
+            syncActiveFileTreeItem(entry.vault, entry.path);
           }
           closeMobileSidebar();
         });
@@ -2926,14 +2947,7 @@
     cachedRawSource = null;
 
     // Highlight active
-    document.querySelectorAll(".tree-item.active").forEach((el) => el.classList.remove("active"));
+    syncActiveFileTreeItem(vaultName, filePath);
-    const selector = `.tree-item[data-vault="${vaultName}"][data-path="${CSS.escape(filePath)}"]`;
-    try {
-      const active = document.querySelector(selector);
-      if (active) active.classList.add("active");
-    } catch (e) {
-      /* selector might fail on special chars */
-    }
 
     // Show loading state while fetching
     const area = document.getElementById("content-area");