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/projects.py

@@ -42,6 +42,32 @@ async def list_projects() -> dict:
     return {"projects": [p.to_dict() for p in rows]}
 
 
+# Done milestones a project read still lists: the recent ones say what just
+# finished, and older ones are a list_milestones call away (#4045).
+_DONE_MILESTONES_KEPT = 5
+
+
+async def _milestone_block(uid: int, project_id: int) -> dict:
+    """`milestone_summary` for a project read, brief and bounded (#4045).
+
+    Every open milestone plus the most recent done ones, without plan bodies.
+    `milestone_summary_omitted` is attached only when older done milestones
+    were left out, and names the calls that reach them (#2483).
+    """
+    rows = await milestones_svc.get_project_milestone_summary(uid, project_id)
+    brief, omitted = milestones_svc.brief_milestone_summary(
+        rows, done_kept=_DONE_MILESTONES_KEPT,
+    )
+    out: dict = {"milestone_summary": brief}
+    if omitted:
+        out["milestone_summary_omitted"] = (
+            f"{omitted} older done milestone(s) not listed. "
+            f"list_milestones({project_id}) lists every milestone; "
+            "get_milestone(id) has one milestone's plan and steps."
+        )
+    return out
+
+
 async def enter_project(project_id: int) -> dict:
     """Session-start handshake: load full context for working on a project.
 
@@ -63,6 +89,11 @@ async def enter_project(project_id: int) -> dict:
     open_tasks, recent_notes, design_system, systems, pattern_coverage —
     plus systems_bootstrap, present only when it applies (see below).
 
+    `milestone_summary` lists every open milestone and the most recently
+    finished done ones, each with its description and progress but NOT its
+    plan: get_milestone(id) reads a plan. `milestone_summary_omitted` appears
+    only when older done milestones were left out, and says how many.
+
     `pattern_coverage` (usually null) is the shape-accounting line — how many
     of the bound repo's extracted shapes carry a classification against canon
     (note 2786) — e.g. "shape accounting: 3100/4573 shapes accounted for —
@@ -120,9 +151,7 @@ async def enter_project(project_id: int) -> dict:
     applicable = await rulebooks_svc.get_applicable_rules(
         project_id=project_id, user_id=uid,
     )
-    milestone_summary = await milestones_svc.get_project_milestone_summary(
-        uid, project_id,
-    )
+    milestones = await _milestone_block(uid, project_id)
     open_tasks, _ = await notes_svc.list_notes(
         uid, is_task=True, project_id=project_id,
         status=["todo", "in_progress"], sort="updated_at", limit=10,
@@ -206,7 +235,7 @@ async def enter_project(project_id: int) -> dict:
             for s in systems
         ],
         "design_system": design_system,
-        "milestone_summary": milestone_summary,
+        **milestones,
         **rulebooks_svc.rules_payload(applicable, user_id=uid, source="enter_project"),
         "open_tasks": [
             {
@@ -236,8 +265,10 @@ async def enter_project(project_id: int) -> dict:
 async def get_project(project_id: int) -> dict:
     """Fetch a Scribe project by ID.
 
-    Returns full project fields, a milestone_summary list, and the
-    rulebook-applicable_rules / subscribed_rulebooks pair the assistant
+    Returns full project fields, a milestone_summary list (shaped as in
+    enter_project: open milestones and the recent done ones, no plan bodies,
+    with milestone_summary_omitted when older done ones were left out), and
+    the rulebook-applicable_rules / subscribed_rulebooks pair the assistant
     should consult when working on this project.
     """
     uid = current_user_id()
@@ -245,9 +276,7 @@ async def get_project(project_id: int) -> dict:
     if project is None:
         raise ValueError(f"project {project_id} not found")
     data = project.to_dict()
-    data["milestone_summary"] = await milestones_svc.get_project_milestone_summary(
-        uid, project_id,
-    )
+    data.update(await _milestone_block(uid, project_id))
     applicable = await rulebooks_svc.get_applicable_rules(
         project_id=project_id, user_id=uid,
     )