feat: enhance vision autocomplete service and UI feedback

- Optimized the vision autocomplete service by starting the SSE stream immediately and deriving KB search queries directly from window titles.
- Refactored the service to run KB filesystem pre-computation and agent graph compilation in parallel, improving performance.
- Updated the SuggestionPage component to handle new agent step data, displaying progress indicators for each step.
- Enhanced the CSS for the suggestion tooltip and agent activity indicators, improving the user interface and experience.

surfsense_backend/app/agents/autocomplete/__init__.py

@@ -0,0 +1,11 @@
+"""Agent-based vision autocomplete with scoped filesystem exploration."""
+
+from app.agents.autocomplete.autocomplete_agent import (
+    create_autocomplete_agent,
+    stream_autocomplete_agent,
+)
+
+__all__ = [
+    "create_autocomplete_agent",
+    "stream_autocomplete_agent",
+]