Build the name list instead of mutating Hypothesis's

`drawn.insert(...)` writes into the list `st.lists` handed back. Safe
today -- that strategy builds a fresh list per draw -- but the hazard
class is the kind a fuzzer should not carry: a strategy that ever
handed back a shared or memoized list would turn this into a bug in
the test harness, reported as a bug in the code under test. The
rebuild costs nothing and draws in the same order, so the committed
seed still counts 23 surname splits and one peel.

Also names the shape honestly in the comment above it: the pool CAN
produce that token, it just loses the draw. "cannot deliver on its own"
contradicted the paragraph four lines up.

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

Author: derek73

tests/v2/test_properties.py

@@ -392,16 +392,22 @@ def _names_using(draw: st.DrawFn, lexicon: Lexicon,
     pieces = st.sampled_from(
         vocab + unspaced + glued + ["John", "Smith", "Q.", ",", "(", "'"])
     drawn = draw(st.lists(pieces, min_size=1, max_size=8))
-    # The one shape the pool cannot deliver on its own. Inserted at a
-    # drawn position rather than the front: the stage takes the first
-    # ACTIVATED-script token, not the first token, so a leading Latin
-    # word must not hide it -- and both placements are worth covering.
+    # The one shape the pool does not deliver RELIABLY -- it is in
+    # there, it just loses the draw. Inserted at a drawn position
+    # rather than the front: the stage takes the first ACTIVATED-script
+    # token, not the first token, so a leading Latin word cannot hide
+    # it -- and both placements are worth covering.
     activatable = sorted(
         w + "민준" for w in lexicon.surnames
         if effective_script(w + "민준") in policy.segment_scripts)
     if activatable:
-        drawn.insert(draw(st.integers(0, len(drawn))),
-                     draw(st.sampled_from(activatable)))
+        # rebuilt rather than list.insert()d: st.lists hands back a
+        # fresh list today, so mutating it is safe today, and a
+        # strategy that ever memoized one would make this a bug in the
+        # fuzzer rather than in the code under test
+        at = draw(st.integers(0, len(drawn)))
+        token = draw(st.sampled_from(activatable))
+        drawn = [*drawn[:at], token, *drawn[at:]]
     return " ".join(drawn)