tool call streaming implementation

[shivamhwp]

• on_tool_start_stream events to the buffer.
• use-stream.ts merges partial chunks and marks them complete.
• minor refactor of the prompt, was giving the output parsing failure

Summary by CodeRabbit

• New Features
  • Live tool output streaming with progress and finalization, including improved extraction and checkpoint refresh.
  • New StreamingOutput UI for terminal-like live updates.
  • Google Calendar/Gmail tools now stream progress and results.
  • Enhanced planner/replanner prompts for stricter, schema-based outputs.
  • Safer, richer document previews with error handling and secure URL opening.
  • TooltipButton supports a disabled state.
• Bug Fixes
  • More robust AI message parsing to prevent rendering errors.
  • Improved edit submission validation and error feedback.
• Refactor
  • Consolidated tool utilities and grouped MCP tools for clearer organization.
• Style
  • Minor UI tweaks (icons, colors, font sizing).
• Chores
  • Updated TypeScript; removed an obsolete dev script.