Keyboard navigation improvements across all editors

TiptapEditor.vue (central — applies to all three editors):
- Escape inside editor blurs it and emits 'escape' event to parent

TagInput.vue (central — applies everywhere tags are used):
- ArrowUp/ArrowDown navigate autocomplete suggestion list with visual highlight
- Enter confirms the keyboard-selected suggestion instead of typed text

NoteEditorView, TaskEditorView, WorkspaceNoteEditor (per-editor wiring):
- @escape on TiptapEditor returns focus to the title input (ref="titleRef")
- Ctrl+E from title input or editor main column jumps focus into editor body
- Ctrl+S on title input saves (was already on editor area; now consistent)

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

frontend/src/components/WorkspaceNoteEditor.vue

@@ -47,6 +47,7 @@ const saving = ref(false);
 const tagSuggestions = useTagSuggestions(noteTitle, noteBody, noteTags, () => { dirty.value = true; });
 
 // TipTap editor ref (for MarkdownToolbar)
+const titleRef = ref<HTMLInputElement | null>(null);
 const editorRef = ref<InstanceType<typeof TiptapEditor> | null>(null);
 const tiptapEditor = computed<Editor | null>(() =>
   (editorRef.value?.editor as Editor | undefined) ?? null
@@ -252,10 +253,12 @@ onUnmounted(() => { if (linkCheckTimer) clearTimeout(linkCheckTimer); });
 
       <div class="note-title-row">
         <input
+          ref="titleRef"
           v-model="noteTitle"
           class="note-title-input"
           placeholder="Note title"
           @keydown.ctrl.s.prevent="saveNote"
+          @keydown.ctrl.e.prevent="editorRef?.editor?.commands.focus()"
         />
       </div>
 
@@ -308,8 +311,8 @@ onUnmounted(() => { if (linkCheckTimer) clearTimeout(linkCheckTimer); });
         <button class="btn-dismiss-suggestions" @click="linkSuggestions = []">✕</button>
       </div>
 
-      <div class="editor-area" @keydown.ctrl.s.prevent="saveNote">
-        <TiptapEditor ref="editorRef" v-model="noteBody" />
+      <div class="editor-area" @keydown.ctrl.s.prevent="saveNote" @keydown.ctrl.e.prevent="editorRef?.editor?.commands.focus()">
+        <TiptapEditor ref="editorRef" v-model="noteBody" @escape="titleRef?.focus()" />
       </div>
     </template>