docs: add data types, sizes, and context window budget to agent_dataflow.md
Add per-agent Prompt Size Budget tables (all 17 agents) with data type,
format, and token estimates. Add three new reference sections:
- Section 7: Tool Data Formats & Sizes (20 tools with format, size, limits)
- Section 8: Context Window Budget (model reference + per-agent risk table)
- Section 9: End-to-End Token Estimates (trading ~98K, scanner ~13K tokens)
Co-authored-by: aguzererler <6199053+aguzererler@users.noreply.github.com>