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/services/intent.py

@@ -89,10 +89,16 @@ Rules:
 - "which calendars", "list calendars", "my calendars" → use list_calendars.
 - "create a calendar todo", "add a CalDAV todo" → use create_todo. Default to create_task for general tasks unless the user explicitly mentions CalDAV or calendar todo.
 - "show calendar todos", "list calendar todos" → use list_todos.
+- "find calendar todo", "search calendar todos", "find todo named X" → use search_todos with query=<keyword>.
 - "completed/finished calendar todo" → use complete_todo.
 - "delete/remove calendar todo" → use delete_todo.
 - "remind me X minutes/hours before" an event → convert to reminder_minutes parameter on create_event.
 - When the user asks about events in a time period (e.g. "events in September", "what's on next week", "my schedule for March"), use list_events with date_from/date_to covering that period. Do NOT use search_events for time-based queries — search_events is only for keyword matching against event titles.
+- "delete", "remove", "trash", "get rid of" a note (not a task) → use delete_note with query=<note name/keyword>. NEVER use this for tasks.
+- "delete", "remove", "trash", "get rid of" a task → use delete_task with query=<task name/keyword>. NEVER use this for notes.
+- "read", "open", "show me", "what does X say", "display", "pull up" a specific note → use get_note with query=<note name>.
+- "list my notes", "show notes", "recent notes", "browse notes", "notes tagged X" → use list_notes (with optional q or tags).
+- "tag X with Y", "add tag Y to X", "untag Y from X", "remove tag Y from X" → use update_note with tags=[Y] and tag_mode="add" or "remove".
 - Do NOT wrap the JSON in markdown code fences."""