UX: queue bubbles, dashboard queuing, duplicate confirm buttons, short-note fix

- Dashboard chat: allow typing/sending during streaming (queued in store)
  placeholder updates to "Type to queue…" during generation
- ChatView/WorkspaceView: replace queued chip with actual pending message
  bubbles — light grey, dashed border, "Queued" badge above content; clear
  button below the stack
- ToolCallCard: when tool returns requires_confirmation=True, show
  "Similar content found" label (not "Error"), link to the similar note,
  and "Create Anyway" / "Don't Create" buttons that auto-send the reply
- tools.py: fuzzy title match now returns requires_confirmation=True with
  similar_note data instead of a hard error, so numbered-series notes
  (Lore: X 0, Lore: X 1) can be created with one button click; semantic
  match responses also include similar_note for the link

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

frontend/src/components/DashboardChatInput.vue

@@ -126,7 +126,7 @@ defineExpose({ focus });
         <button
           class="btn-attach"
           @click="toggleNotePicker"
-          :disabled="!store.chatReady || store.streaming"
+          :disabled="!store.chatReady"
           title="Attach a note"
         >
           <svg
@@ -181,17 +181,17 @@ defineExpose({ focus });
         @input="autoResize"
         :placeholder="
           !store.chatReady ? 'Chat unavailable'
-          : store.streaming ? 'Generating response…'
+          : store.streaming ? 'Type to queue… (Enter to queue)'
           : 'Start a new chat… (Enter to send)'
         "
-        :disabled="!store.chatReady || store.streaming"
+        :disabled="!store.chatReady"
         rows="1"
       ></textarea>
 
       <button
         class="btn-send"
         @click="onSubmit"
-        :disabled="!messageInput.trim() || !store.chatReady || store.streaming"
+        :disabled="!messageInput.trim() || !store.chatReady"
       >
         &uarr;
       </button>