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>

tests/unit/test_cowork_turn_request.py

@@ -0,0 +1,76 @@
+"""R04-T04 — unit tests for the UI-state -> request mapping.
+
+Three small rules used to sit inline in ``ui/cowork_tab.py::build_job``, where no
+test could reach them: the turn's prompt is the last message in the working list,
+the history is everything before it, and the confirm-commands flag becomes a gate
+mode. Getting any of them wrong is silent (a duplicated user message, a command
+that stops asking for approval), so they are pinned here.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from cowork_local.application.conversations.cowork_turn_request import (
+    build_cowork_turn_request,
+)
+
+
+def _build(**overrides):
+    base = {
+        "turn_id": "t3",
+        "session_id": "s1",
+        "messages": [{"role": "user", "content": "make me a report"}],
+    }
+    base.update(overrides)
+    return build_cowork_turn_request(**base)
+
+
+def test_the_last_message_becomes_the_prompt_and_the_rest_the_history() -> None:
+    request = _build(messages=[
+        {"role": "user", "content": "earlier"},
+        {"role": "assistant", "content": "sure"},
+        {"role": "user", "content": "now this"},
+    ])
+
+    assert request.prompt == "now this"
+    assert request.messages == ({"role": "user", "content": "earlier"},
+                                {"role": "assistant", "content": "sure"})
+
+
+def test_an_empty_working_list_yields_an_empty_prompt() -> None:
+    # Defensive: a turn with no message at all must not raise on messages[-1].
+    request = _build(messages=[])
+
+    assert request.prompt == ""
+    assert request.messages == ()
+
+
+def test_confirming_commands_puts_the_turn_in_confirm_gate_mode() -> None:
+    assert _build(confirm_commands=True).gate_mode == "confirm"
+    assert _build(confirm_commands=False).gate_mode == "auto"
+    assert _build().gate_mode == "auto"          # auto-run is the default
+
+
+def test_the_captured_widget_state_is_carried_into_the_request() -> None:
+    request = _build(
+        surface="cowork", project_id="p7", title="Weekly report",
+        provider_id="anthropic", model="claude-sonnet-4-6",
+        instructions="PROJECT RULES", output_dir="out/.turns/t3",
+        home_output_root="out", agent_role="cowork",
+    )
+
+    assert (request.turn_id, request.session_id) == ("t3", "s1")
+    assert (request.surface, request.project_id, request.title) == \
+           ("cowork", "p7", "Weekly report")
+    assert (request.provider_id, request.model) == ("anthropic", "claude-sonnet-4-6")
+    assert request.project_context == "PROJECT RULES"
+    assert request.output_dir == Path("out/.turns/t3")
+    assert request.home_output_root == Path("out")
+    assert request.agent_role == "cowork"
+
+
+def test_the_prompt_survives_a_message_whose_content_is_missing() -> None:
+    request = _build(messages=[{"role": "user"}])
+
+    assert request.prompt == ""