refactor(routes): one supersession seam for REST and MCP; PUT/PATCH notes share a handler; shared mask/not-found/caller helpers (#2829, milestone 296 area 5)

Reading the 28 route modules against each other and against the MCP tools:
- routes/notes.py carried a PUT and a PATCH handler that were the same
  function minus the supersedes contract on one of them — one handler now
  serves both verbs, so both carry it.
- The two _attach_supersession copies (REST + MCP) become
  supersession_svc.attach_relations(uid, note_id, data, hint=) — the seam
  the two surfaces must agree through; only the agent surface adds the
  one-sentence reading hint.
- Three local _uid() wrappers over g.user.id → scribe.auth.get_current_user_id
  like every other module; design_systems' private _not_found → routes.utils.
  not_found; the four "********" literals → settings_svc.SECRET_MASK with the
  read/write contract written once.
- routes/plugin.py: the project_id/repo resolution block and the
  comma-separated id parse were copied into three endpoints — _project_scope()
  and _int_list() now.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/scribe/routes/rulebooks.py

@@ -1,29 +1,26 @@
 """Rulebook / topic REST endpoints.
 
-Wraps services/rulebooks.py. Standard Scribe auth: g.user.id is the
+Wraps services/rulebooks.py. Standard Scribe auth: get_current_user_id() is the
 authenticated owner; the service enforces ownership scoping.
 """
 from __future__ import annotations
 
-from quart import Blueprint, g, jsonify, request
+from quart import Blueprint, jsonify, request
 
-from scribe.auth import login_required
+from scribe.auth import get_current_user_id, login_required
 import scribe.services.rulebooks as rulebooks_svc
 from scribe.services.trash import delete as trash_delete
 
 rulebooks_bp = Blueprint("rulebooks", __name__, url_prefix="/api")
 
 
-def _uid() -> int:
-    return g.user.id
-
 
 # ── Rulebooks ───────────────────────────────────────────────────────────
 
 @rulebooks_bp.get("/rulebooks")
 @login_required
 async def list_rulebooks():
-    rows = await rulebooks_svc.list_rulebooks(_uid())
+    rows = await rulebooks_svc.list_rulebooks(get_current_user_id())
     return jsonify({"rulebooks": [rb.to_dict() for rb in rows]})
 
 
@@ -35,7 +32,7 @@ async def create_rulebook():
     if not title:
         return jsonify({"error": "title is required"}), 400
     rb = await rulebooks_svc.create_rulebook(
-        user_id=_uid(),
+        user_id=get_current_user_id(),
         title=title,
         description=data.get("description", ""),
     )
@@ -45,7 +42,7 @@ async def create_rulebook():
 @rulebooks_bp.get("/rulebooks/<int:rulebook_id>")
 @login_required
 async def get_rulebook(rulebook_id: int):
-    rb = await rulebooks_svc.get_rulebook(rulebook_id, _uid())
+    rb = await rulebooks_svc.get_rulebook(rulebook_id, get_current_user_id())
     if rb is None:
         return jsonify({"error": "rulebook not found"}), 404
     return jsonify(rb.to_dict())
@@ -56,7 +53,7 @@ async def get_rulebook(rulebook_id: int):
 async def update_rulebook(rulebook_id: int):
     data = await request.get_json() or {}
     fields = {k: v for k, v in data.items() if k in ("title", "description", "always_on")}
-    rb = await rulebooks_svc.update_rulebook(rulebook_id, _uid(), **fields)
+    rb = await rulebooks_svc.update_rulebook(rulebook_id, get_current_user_id(), **fields)
     if rb is None:
         return jsonify({"error": "rulebook not found"}), 404
     return jsonify(rb.to_dict())
@@ -65,7 +62,7 @@ async def update_rulebook(rulebook_id: int):
 @rulebooks_bp.delete("/rulebooks/<int:rulebook_id>")
 @login_required
 async def delete_rulebook(rulebook_id: int):
-    await trash_delete(_uid(), "rulebook", rulebook_id)
+    await trash_delete(get_current_user_id(), "rulebook", rulebook_id)
     return "", 204
 
 
@@ -75,7 +72,7 @@ async def delete_rulebook(rulebook_id: int):
 @login_required
 async def list_topics(rulebook_id: int):
     try:
-        rows = await rulebooks_svc.list_topics(rulebook_id, _uid())
+        rows = await rulebooks_svc.list_topics(rulebook_id, get_current_user_id())
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
     return jsonify({"topics": [t.to_dict() for t in rows]})
@@ -91,7 +88,7 @@ async def create_topic(rulebook_id: int):
     try:
         topic = await rulebooks_svc.create_topic(
             rulebook_id=rulebook_id,
-            user_id=_uid(),
+            user_id=get_current_user_id(),
             title=title,
             description=data.get("description", ""),
             order_index=data.get("order_index", 0),
@@ -109,7 +106,7 @@ async def update_topic(topic_id: int):
         k: v for k, v in data.items()
         if k in ("title", "description", "order_index")
     }
-    topic = await rulebooks_svc.update_topic(topic_id, _uid(), **fields)
+    topic = await rulebooks_svc.update_topic(topic_id, get_current_user_id(), **fields)
     if topic is None:
         return jsonify({"error": "topic not found"}), 404
     return jsonify(topic.to_dict())
@@ -118,7 +115,7 @@ async def update_topic(topic_id: int):
 @rulebooks_bp.delete("/rulebook-topics/<int:topic_id>")
 @login_required
 async def delete_topic(topic_id: int):
-    if await trash_delete(_uid(), "topic", topic_id) is None:
+    if await trash_delete(get_current_user_id(), "topic", topic_id) is None:
         return jsonify({"error": "topic not found"}), 404
     return "", 204
 
@@ -140,7 +137,7 @@ async def list_rules():
         return jsonify({"error": "rulebook_id, topic_id, project_id must be integers"}), 400
 
     rows = await rulebooks_svc.list_rules(
-        user_id=_uid(),
+        user_id=get_current_user_id(),
         rulebook_id=rulebook_id,
         topic_id=topic_id,
         project_id=project_id,
@@ -159,7 +156,7 @@ async def create_rule(topic_id: int):
     try:
         rule = await rulebooks_svc.create_rule(
             topic_id=topic_id,
-            user_id=_uid(),
+            user_id=get_current_user_id(),
             title=title,
             statement=statement,
             why=data.get("why", ""),
@@ -174,7 +171,7 @@ async def create_rule(topic_id: int):
 @rulebooks_bp.get("/rules/<int:rule_id>")
 @login_required
 async def get_rule(rule_id: int):
-    rule = await rulebooks_svc.get_rule(rule_id, _uid())
+    rule = await rulebooks_svc.get_rule(rule_id, get_current_user_id())
     if rule is None:
         return jsonify({"error": "rule not found"}), 404
     return jsonify(rule.to_dict())
@@ -188,7 +185,7 @@ async def update_rule(rule_id: int):
         k: v for k, v in data.items()
         if k in ("title", "statement", "why", "how_to_apply", "order_index")
     }
-    rule = await rulebooks_svc.update_rule(rule_id, _uid(), **fields)
+    rule = await rulebooks_svc.update_rule(rule_id, get_current_user_id(), **fields)
     if rule is None:
         return jsonify({"error": "rule not found"}), 404
     return jsonify(rule.to_dict())
@@ -197,7 +194,7 @@ async def update_rule(rule_id: int):
 @rulebooks_bp.delete("/rules/<int:rule_id>")
 @login_required
 async def delete_rule(rule_id: int):
-    if await trash_delete(_uid(), "rule", rule_id) is None:
+    if await trash_delete(get_current_user_id(), "rule", rule_id) is None:
         return jsonify({"error": "rule not found"}), 404
     return "", 204
 
@@ -213,7 +210,7 @@ async def subscribe_project(project_id: int):
         return jsonify({"error": "rulebook_id is required"}), 400
     try:
         await rulebooks_svc.subscribe_project(
-            project_id=project_id, rulebook_id=int(rulebook_id), user_id=_uid(),
+            project_id=project_id, rulebook_id=int(rulebook_id), user_id=get_current_user_id(),
         )
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
@@ -227,7 +224,7 @@ async def subscribe_project(project_id: int):
 async def unsubscribe_project(project_id: int, rulebook_id: int):
     try:
         await rulebooks_svc.unsubscribe_project(
-            project_id=project_id, rulebook_id=rulebook_id, user_id=_uid(),
+            project_id=project_id, rulebook_id=rulebook_id, user_id=get_current_user_id(),
         )
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
@@ -238,7 +235,7 @@ async def unsubscribe_project(project_id: int, rulebook_id: int):
 @login_required
 async def get_project_rules(project_id: int):
     result = await rulebooks_svc.get_applicable_rules(
-        project_id=project_id, user_id=_uid(),
+        project_id=project_id, user_id=get_current_user_id(),
     )
     return jsonify(result)
 
@@ -248,7 +245,7 @@ async def get_project_rules(project_id: int):
 async def suppress_project_rule(project_id: int, rule_id: int):
     try:
         await rulebooks_svc.suppress_rule_for_project(
-            project_id=project_id, rule_id=rule_id, user_id=_uid(),
+            project_id=project_id, rule_id=rule_id, user_id=get_current_user_id(),
         )
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
@@ -260,7 +257,7 @@ async def suppress_project_rule(project_id: int, rule_id: int):
 async def unsuppress_project_rule(project_id: int, rule_id: int):
     try:
         await rulebooks_svc.unsuppress_rule_for_project(
-            project_id=project_id, rule_id=rule_id, user_id=_uid(),
+            project_id=project_id, rule_id=rule_id, user_id=get_current_user_id(),
         )
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
@@ -272,7 +269,7 @@ async def unsuppress_project_rule(project_id: int, rule_id: int):
 async def suppress_project_topic(project_id: int, topic_id: int):
     try:
         await rulebooks_svc.suppress_topic_for_project(
-            project_id=project_id, topic_id=topic_id, user_id=_uid(),
+            project_id=project_id, topic_id=topic_id, user_id=get_current_user_id(),
         )
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
@@ -284,7 +281,7 @@ async def suppress_project_topic(project_id: int, topic_id: int):
 async def unsuppress_project_topic(project_id: int, topic_id: int):
     try:
         await rulebooks_svc.unsuppress_topic_for_project(
-            project_id=project_id, topic_id=topic_id, user_id=_uid(),
+            project_id=project_id, topic_id=topic_id, user_id=get_current_user_id(),
         )
     except ValueError as exc:
         return jsonify({"error": str(exc)}), 404
@@ -303,7 +300,7 @@ async def create_project_rule(project_id: int):
     try:
         rule = await rulebooks_svc.create_project_rule(
             project_id=project_id,
-            user_id=_uid(),
+            user_id=get_current_user_id(),
             title=title,
             statement=statement,
             why=data.get("why", ""),