feat: support role-based agent prompts

tests/test_prompt.py

@@ -259,3 +259,66 @@ def test_extract_test_commands_no_section(tmp_path: Path) -> None:
 
     commands = _extract_test_commands_from_claude(tmp_path)
     assert commands == []
+
+
+def test_generate_agent_prompt_with_role(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Role: Architecture Agent\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "You are an architecture agent." in prompt
+
+
+def test_generate_agent_prompt_default_role_when_missing(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "You are an implementation agent." in prompt
+
+
+def test_generate_agent_prompt_with_empty_role_defaults(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Role:\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "You are an implementation agent." in prompt
+
+
+def test_generate_agent_prompt_with_custom_role(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Role: DevOps Engineer\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "You are a devops engineer." in prompt