Feature/delta team/epic r04 (#7)

## Summary

epic r04 - begin refactor

## Change Type

- [x] Cowork feature
- [ ] Bug fix
- [ ] Core AI contribution
- [ ] Test / hardening
- [ ] Performance
- [ ] Documentation

## Related Work

Cowork Task:

Core Repo: http://34.143.229.138/gitea-admin/fsg-ai-core-assets

Core AI Issue:

Core Task:

Related PR:

## Scope

What is intentionally included?

What is intentionally NOT included?

## Validation

- [ ] Unit tests
- [ ] Integration tests
- [ ] Manual verification
- [ ] Regression check

Commands / evidence:

## Security Impact

Permission / credential / network / customer data impact:

## Compatibility

- [ ] No breaking change
- [ ] Breaking change documented

## Reviewer Notes

Anything Cowork reviewers should pay attention to.

---------

Co-authored-by: Anh Tran Nguyen Minh <anhtnm1@fpt.com>
Co-authored-by: Huong Le Thi Thien <huongltt35@fpt.com>
Co-authored-by: Nam Pham Dinh Thanh <nampdt@fpt.com>
Co-authored-by: Vu Dam Tuan <vudt15@fpt.com>
Co-authored-by: Hiep Ha Van <hiephv3@fpt.com>
Co-authored-by: Lam Hoang Van <lamhv7@fpt.com>
Reviewed-on: #7
Co-authored-by: Duy Le Huu <duylh19@fpt.com>

presentation/chat/chat_helpers.py

@@ -0,0 +1,41 @@
+"""Hàm và bảng tra dùng chung trong khung chat — R08-T06.
+
+Thuần hàm, không widget. Gom về đây vì cả năm file trong gói đều hỏi tới.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+_PLAN_ICONS = {"pending": "○", "running": "▶", "done": "✓", "error": "✗"}
+
+
+
+def _format_plan_steps(steps) -> str:
+    """Render plan steps ``[{title, status}]`` as an icon checklist for the chat."""
+    lines = []
+    for s in steps or []:
+        title = str((s or {}).get("title", "")).strip()
+        if not title:
+            continue
+        icon = _PLAN_ICONS.get(str((s or {}).get("status", "pending")).lower(), "○")
+        lines.append(f"{icon} {title}")
+    return "\n".join(lines)
+
+
+def _is_scratch(path: str) -> bool:
+    """True for helper/intermediate files (kept out of the Output list)."""
+    try:
+        return ".scratch" in Path(path).parts
+    except Exception:  # noqa: BLE001
+        return False
+
+
+_TOOL_STATUS = {
+    "save_file": "chat.creating",
+    "write_file": "chat.creating",
+    "run_command": "chat.creating",
+    "edit_file": "chat.editing",
+    "install_package": "chat.installing",
+    "read_file": "chat.reading",
+}