v3: inline edit forms and the narrow-viewport search row ease open instead of popping in

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/components/AppHeader.tsx

@@ -117,14 +117,23 @@ export function AppHeader(
         </nav>
       </header>
 
-      {searchExpanded && (
-        <div className="header-search-below">
-          <SearchBar
-            expanded={searchExpanded}
-            onExpandedChange={setSearchExpanded}
-          />
+      {/* Stays mounted so the row can slide open and shut; `inert` keeps the
+          collapsed input out of the tab order. */}
+      <div
+        className={`header-search-reveal${
+          searchExpanded ? " header-search-reveal--open" : ""
+        }`}
+        inert={!searchExpanded}
+      >
+        <div className="header-search-reveal-clip">
+          <div className="header-search-below">
+            <SearchBar
+              expanded={searchExpanded}
+              onExpandedChange={setSearchExpanded}
+            />
+          </div>
         </div>
-      )}
+      </div>
 
       {wsStatus === "disconnected" && wsErrorMessage && (
         <div className="app-header-status" role="alert">