fix(mcp): project reads list milestones without their plans, and cap done ones (#4045)

enter_project returned every milestone's full plan body. On a project with 39
milestones the handshake came to ~222k characters, 168k of them bodies (110k
from done milestones). That is past what an MCP client accepts as a tool
result, so the call meant to orient a session arrived as a file to page
through. It grows with a project's history, so any long-lived project on any
install gets there.

- brief_milestone_summary (services/milestones.py) trims summary rows to the
  listing fields: id, title, description, status, order_index and progress.
  The plan is get_milestone's job. user_id, project_id and timestamps repeat
  what the caller knows.
- enter_project and get_project share one block: every open milestone plus
  the 5 most recently updated done ones, in order. milestone_summary_omitted
  is attached only when older done ones were left out, and names
  list_milestones and get_milestone.
- list_milestones lists every milestone, done included, without bodies. It is
  the call the omitted line points to, and it had the same size problem.
- The REST project summary is unchanged; the web UI reads it.

Tests: trimming, the done cap and its order, the omitted key present and
absent, get_project and list_milestones, and a size ceiling on enter_project's
milestone block for a 200-milestone history.

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

src/scribe/mcp/tools/milestones.py

@@ -22,12 +22,15 @@ from scribe.services.record_refs import refuse_guessed_ids
 async def list_milestones(project_id: int) -> dict:
     """List milestones for a Scribe project, ordered by order_index.
 
-    Returns id, title, description, body (the plan/design), status
-    (active/done), order_index, and task counts.
+    Returns every milestone, done ones included: id, title, description,
+    status (active/done), order_index and progress (total, completed, pct,
+    status_counts). The plan itself is not listed: get_milestone(id) returns a
+    milestone's body and its steps.
     """
     uid = current_user_id()
     rows = await milestones_svc.get_project_milestone_summary(uid, project_id)
-    return {"milestones": rows}
+    brief, _ = milestones_svc.brief_milestone_summary(rows)
+    return {"milestones": brief}
 
 
 async def get_milestone(milestone_id: int) -> dict: