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>

src/fabledassistant/routes/chat.py

@@ -23,6 +23,7 @@ from fabledassistant.services.generation_buffer import (
     get_buffer,
 )
 from fabledassistant.services.generation_task import run_generation
+from fabledassistant.services.notes import get_notes_by_ids
 from fabledassistant.services.settings import get_setting
 
 logger = logging.getLogger(__name__)
@@ -62,7 +63,14 @@ async def get_conversation_route(conv_id: int):
     if conv is None:
         return jsonify({"error": "Conversation not found"}), 404
     result = conv.to_dict()
-    result["messages"] = [m.to_dict() for m in conv.messages]
+    note_ids = [m.context_note_id for m in conv.messages if m.context_note_id]
+    note_map = await get_notes_by_ids(uid, note_ids) if note_ids else {}
+    result["messages"] = []
+    for m in conv.messages:
+        msg_dict = m.to_dict()
+        if m.context_note_id and m.context_note_id in note_map:
+            msg_dict["context_note_title"] = note_map[m.context_note_id].title
+        result["messages"].append(msg_dict)
     return jsonify(result)