fix(mcp): list tools return rows that say what a record is, not what it says (#4061)

list_tasks returned every row's to_dict(), body included: a project's todo list
came to 93-165k characters, past what an MCP client accepts inline, so the list
arrived as a file to page through (the #4045 failure, one call over).

- notes.brief_row: id, title, type, project, tags, updated_at; for tasks,
  status, kind, priority, milestone id and title; description, parent and due
  date only when set.
- milestones.titles_for: one query for the milestone titles a page of rows
  names.
- Brief rows on list_tasks, list_notes, get_milestone's steps, get_system and
  list_system_records. get_task / get_note / get_snippet read a record in full,
  and each docstring says so.
- tests/test_list_rows_brief.py pins the ceiling: 100 rows of ~5k-character
  step plans stay under 40k characters.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01821k5B3Ysecp9fNYs92Kuy

tests/test_mcp_tool_milestones.py

@@ -6,7 +6,7 @@ import pytest
 from scribe.mcp.tools.milestones import (
     list_milestones, get_milestone, create_milestone, update_milestone,
 )
-from tests.helpers import fake_milestone
+from tests.helpers import fake_milestone, fake_task
 
 
 pytestmark = pytest.mark.usefixtures("_bind_user")
@@ -111,8 +111,7 @@ async def test_update_milestone_sends_body():
 @pytest.mark.asyncio
 async def test_get_milestone_returns_body_steps_and_rules():
     m = fake_milestone(id=5, project_id=3, body="## Goal")
-    step = MagicMock()
-    step.to_dict.return_value = {"id": 9, "title": "step 1", "status": "todo"}
+    step = fake_task(id=9, title="step 1", milestone_id=5, body="a long step body")
     applicable = {"rules": [{"id": 1, "title": "r"}], "truncated": False,
                   "project_rules": [{"id": 3, "title": "own"}]}
     with patch("scribe.mcp.tools.milestones.milestones_svc.get_milestone",
@@ -126,7 +125,10 @@ async def test_get_milestone_returns_body_steps_and_rules():
         out = await get_milestone(milestone_id=5)
     assert out["milestone"]["body"] == "## Goal"
     assert out["milestone"]["total"] == 1
-    assert out["steps"] == [{"id": 9, "title": "step 1", "status": "todo"}]
+    assert [(s["id"], s["title"], s["status"]) for s in out["steps"]] == [(9, "step 1", "todo")]
+    # A step's body is get_task's job (#4061); its placement is not.
+    assert "body" not in out["steps"][0]
+    assert out["steps"][0]["milestone_title"] == m.title
     assert out["applicable_rules"] == [{"id": 1, "title": "r"}]