fix: AI loop prevention (no tools on last iteration), calendar button first, mail filter in toolbar, AI folder rename query invalidation

frontend/src/pages/Mail.tsx

@@ -594,6 +594,43 @@ export function MailPage() {
         onSearch: handleSearch,
         onClick: () => {},
       },
+      // FilterPanel — SavedFilterBar + TagSelector
+      {
+        id: 'filter-panel',
+        plugin: 'mail',
+        label: 'Filter',
+        type: 'custom' as const,
+        group: 'filter',
+        customComponent: (
+          <SavedFilterBar
+            entityType="mail"
+            currentFilters={{ search: searchQuery, sortBy, sortOrder, folderId: selectedFolderId }}
+            onApplyFilter={(criteria) => {
+              if (criteria.search !== undefined) handleSearch(criteria.search);
+              if (criteria.sortBy) setSortBy(criteria.sortBy as 'date' | 'from' | 'subject');
+              if (criteria.sortOrder) setSortOrder(criteria.sortOrder as 'asc' | 'desc');
+            }}
+          />
+        ),
+        onClick: () => {},
+      },
+      {
+        id: 'tag-filter',
+        plugin: 'mail',
+        label: 'Tags',
+        type: 'custom' as const,
+        group: 'filter',
+        customComponent: (
+          <TagSelector
+            entityType="file"
+            entityId={selectedMail?.id ?? ''}
+            selectedTags={selectedTags}
+            onChange={setSelectedTags}
+            placeholder={t('tags.selectPlaceholder', 'Tags filtern...')}
+          />
+        ),
+        onClick: () => {},
+      },
       {
         id: 'compose',
         plugin: 'mail',
@@ -814,27 +851,6 @@ export function MailPage() {
           className="border-r border-secondary-200 bg-white"
           data-testid="mail-list-pane"
         >
-          {/* Saved filter bar + tag selector */}
-          <div className="flex items-center gap-2 px-3 py-2 border-b border-secondary-200 bg-secondary-50 flex-wrap" data-testid="mail-filter-bar">
-            <SavedFilterBar
-              entityType="mail"
-              currentFilters={{ search: searchQuery, sortBy, sortOrder, folderId: selectedFolderId }}
-              onApplyFilter={(criteria) => {
-                if (criteria.search !== undefined) handleSearch(criteria.search);
-                if (criteria.sortBy) setSortBy(criteria.sortBy as 'date' | 'from' | 'subject');
-                if (criteria.sortOrder) setSortOrder(criteria.sortOrder as 'asc' | 'desc');
-              }}
-            />
-            <div className="flex-1 min-w-[180px]" data-testid="mail-tag-selector">
-              <TagSelector
-                entityType="file"
-                entityId={selectedMail?.id ?? ''}
-                selectedTags={selectedTags}
-                onChange={setSelectedTags}
-                placeholder={t('tags.selectPlaceholder', 'Tags filtern...')}
-              />
-            </div>
-          </div>
           <MailList
             mails={mails}
             selectedMailId={selectedMail?.id || null}