Active user attribute set, latest activities, guarded changes to used values, artefact links, durations and averages; irreversible showcase step

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: sonnet
Assistant-Process: 295952@bnt-lap001
Assistant-Session: e93f64ad-516c-46eb-9666-aad8d300c477

rtut/attrs.py

@@ -70,7 +70,7 @@ def load_set(path: Path) -> Doc:
 class Registry:
     """Everything found under one or more repository roots."""
 
-    def __init__(self, roots: list[Path]):
+    def __init__(self, roots: list[Path], extra_sets: dict[str, Doc] | None = None):
         self.roots = [Path(r) for r in roots]
         self.sets: dict[str, Doc] = {}
         self.projects: dict[str, Doc] = {}
@@ -85,6 +85,8 @@ class Registry:
                 d = _load(f, "project.schema.json"); self.templates[d.id] = d
             for f in P.discover(r):
                 pk = P.load(f); self.packs[pk.id] = pk
+        for sid, doc in (extra_sets or {}).items():          # app-level sets (e.g. the user): repository sets win
+            self.sets.setdefault(sid, doc)
 
 
 def set_layers(reg: Registry, set_id: str, _seen: tuple = ()) -> list[tuple[str, dict]]: