Change tool calls display

[camilleAND]

Purpose

Make tool calls in the chat clearer and less noisy: compact expandable cards with readable status, instead of a generic "Search..." / "Summarizing..." loader while tools run.

Proposal

• Add ToolCard with collapsed header (tool name + status) and expandable input/output/error details
• Add ToolInvocationTimeline to stack multiple tool calls with a visual connector
• Centralize tool labels, status, and readable previews in toolCardUtils
• Show the animated assistant Loader while a tool is running
• Keep special cases for conversation_resume and document_parsing errors
• Add unit tests for ToolCard, ToolInvocationTimeline, and toolCardUtils

[camilleAND]

#605