Add persistent context sidebar, note title fix, and expanded tool suite

Context sidebar + note title:
- ChatView: replace ephemeral context pills with a persistent right-panel sidebar;
  auto-found notes accumulate across turns; attached note shows with pin icon;
  × button excludes a note from future auto-search; hidden on mobile
- routes/chat.py: batch-fetch note titles via get_notes_by_ids() and inject
  context_note_title into each message dict at conversation load time
- notes.py: add get_notes_by_ids() batch fetch helper
- types/chat.ts: add context_note_title field to Message interface
- stores/chat.ts: sendMessage accepts optional 5th arg contextNoteTitle,
  included in optimistic user message
- ChatMessage.vue: context badge shows note title instead of 'Note #N'

Expanded LLM tool suite (all with intent router rules + ToolCallCard display):
- delete_note / delete_task: permanent delete with user confirmation (write tool),
  type-safe (refuse to delete wrong type), clears note context cache on success
- get_note: fetch full note body by query (search_notes returns only 200-char preview)
- list_notes: browse notes by recency/keyword/tags with limit; notes only
- update_note: add tags + tag_mode (replace/add/remove) parameters
- search_notes: add optional type filter ("note" | "task")
- search_todos (CalDAV): keyword-filter todos, companion to list_todos
- caldav.py: add search_todos() built on top of list_todos()
- generation_task.py: register new tools in _WRITE_TOOLS, _TOOL_LABELS, _TOOL_ACTIONS
- llm.py: update available actions list and guidance in system prompt
- intent.py: routing rules for all new tools

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

frontend/src/components/ChatMessage.vue

@@ -81,7 +81,7 @@ const timingParts = computed((): string[] => {
           class="context-badge"
         >
           <router-link :to="`/notes/${message.context_note_id}`">
-            Note #{{ message.context_note_id }}
+            {{ message.context_note_title || `Note #${message.context_note_id}` }}
           </router-link>
         </div>
       </div>

frontend/src/components/ToolCallCard.vue

@@ -20,6 +20,14 @@ const label = computed(() => {
       return "Created note";
     case "note_updated":
       return "Updated note";
+    case "note_deleted":
+      return "Deleted note";
+    case "task_deleted":
+      return "Deleted task";
+    case "note_content":
+      return "Note";
+    case "notes_list":
+      return "Notes";
     case "tasks":
       return "Tasks";
     case "todo_updated":
@@ -166,6 +174,32 @@ const searchResults = computed(() => {
   return results && results.length > 0 ? results : null;
 });
 
+const deletedNote = computed(() => {
+  const data = props.toolCall.result.data;
+  const type = props.toolCall.result.type;
+  if (!data || (type !== "note_deleted" && type !== "task_deleted")) return null;
+  return data as { id: number; title: string };
+});
+
+const noteContent = computed(() => {
+  const data = props.toolCall.result.data;
+  if (!data || props.toolCall.result.type !== "note_content") return null;
+  return data as { id: number; title: string; body: string; tags: string[] };
+});
+
+const noteList = computed(() => {
+  const data = props.toolCall.result.data;
+  if (!data || props.toolCall.result.type !== "notes_list") return null;
+  const results = data.results as Array<{ id: number; title: string; tags: string[]; preview: string }> | undefined;
+  return results ?? [];
+});
+
+const noteListCount = computed(() => {
+  const data = props.toolCall.result.data;
+  if (!data || props.toolCall.result.type !== "notes_list") return 0;
+  return (data.total as number) ?? 0;
+});
+
 async function applyTag(tag: string) {
   if (!noteId.value || appliedTags.value.has(tag) || applyingTag.value) return;
   applyingTag.value = tag;
@@ -189,6 +223,30 @@ async function applyTag(tag: string) {
     <template v-else-if="toolCall.status === 'error'">
       <span class="tool-error">{{ toolCall.result.error }}</span>
     </template>
+    <template v-else-if="deletedNote">
+      <span class="tool-deleted">{{ deletedNote.title || "Untitled" }}</span>
+    </template>
+    <template v-else-if="noteContent">
+      <router-link :to="`/notes/${noteContent.id}`" class="tool-link">{{ noteContent.title || "Untitled" }}</router-link>
+      <span v-if="noteContent.tags.length" class="tool-note-tags">
+        <span v-for="tag in noteContent.tags" :key="tag" class="tool-note-tag">#{{ tag }}</span>
+      </span>
+    </template>
+    <template v-else-if="noteList !== null">
+      <span class="tool-search-info">{{ noteListCount }} found</span>
+      <div v-if="noteList.length > 0" class="tool-search-results">
+        <router-link
+          v-for="n in noteList.slice(0, 8)"
+          :key="n.id"
+          :to="`/notes/${n.id}`"
+          class="tool-search-item"
+        >
+          {{ n.title || "Untitled" }}
+        </router-link>
+        <span v-if="noteList.length > 8" class="tool-event-more">+{{ noteList.length - 8 }} more</span>
+      </div>
+      <span v-else class="tool-search-info">No notes found</span>
+    </template>
     <template v-else-if="searchResults">
       <span class="tool-search-info">{{ (toolCall.result.data?.total as number) ?? 0 }} found</span>
       <div class="tool-search-results">
@@ -380,6 +438,16 @@ async function applyTag(tag: string) {
   text-decoration: line-through;
   opacity: 0.7;
 }
+.tool-note-tags {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.2rem;
+  width: 100%;
+}
+.tool-note-tag {
+  font-size: 0.72rem;
+  color: var(--color-text-muted);
+}
 .tool-task-priority {
   font-size: 0.7rem;
   font-weight: 600;