feat(reuse): recording model becomes the pattern library — every shape at first build (#2687)

Decision #2686: snippets are the project's pattern library, not a dedup
net. The floor, the reusing-code skill, and the snippet tool docstrings
now state the proactive model — record every shape the first time it is
built, with no will-it-recur judgment, and start later instances from
the recorded shape; second-copy consolidation stays as the backstop.
The floor guard test pins all three elements (tool, first-build trigger,
backstop) so the model cannot silently regress to the reactive wording.

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

tests/test_instruction_surfaces_agree.py

@@ -129,21 +129,23 @@ def test_floor_states_the_systems_reflex():
 
 
 def test_floor_names_the_snippet_recording_triggers():
-    """The recording half of reuse needs NAMED trigger moments on the floor.
+    """The floor must state the pattern-library recording model, by name.
 
-    #2664's behavioral finding: with recording guidance as a trailing clause of
-    the reuse bullet, zero snippets were ever recorded outside sessions already
-    thinking about snippets — extracting a shared component (Roundtable's
-    BaseModal) produced task prose and no record. The floor must name the
-    moments, not just the tool.
+    #2664's behavioral finding: recording guidance as a trailing clause of the
+    reuse bullet converted zero times outside snippet-minded sessions. The
+    2026-08-16 ruling (decision #2686) then replaced the reactive model
+    entirely: every shape is recorded at FIRST build — no "will it recur?"
+    judgment — and second-copy consolidation is only the backstop. The floor
+    is the delivery surface for that reflex, so all three elements must stay
+    stated: the tool, the first-build trigger, and the backstop.
     """
     floor = (ROOT / "plugin" / "hooks" / "scribe_static_context.md").read_text()
-    for needle in ("create_snippet", "second copy"):
+    for needle in ("create_snippet", "first build", "second copy"):
         assert needle in floor, (
             f"plugin/hooks/scribe_static_context.md no longer states the "
-            f"snippet-recording trigger ({needle!r}) — the record-as-you-build "
-            f"reflex must be stated on the floor with its trigger moments "
-            f"(#2664)."
+            f"snippet-recording model ({needle!r}) — record-every-shape-at-"
+            f"first-build with second-copy consolidation as the backstop must "
+            f"be stated on the floor (#2664, decision #2686)."
         )