Answer the review, and keep the opening node's bank

Nine findings from a review of the phase-14 stack. The one about a retry
withdrawing a memory is not a bug — a memory anchored to a node describes that
node, and it goes when the node goes. The root is the exception, and it is the
only one: migration 62 parked every memory written before memories had
coordinates on depth 0, so withdrawing the opening node would retire a whole
bank nobody attached there. A memory with no source range covers no story and
now stays; a summary that genuinely ends there is still withdrawn.

The rest are repairs.

* The adventure list quoted whichever attempt was written last rather than the
  one the story tells, so switching back left the index disagreeing with the
  page.
* A v1 import gave a typed memory no depth, rebuilding the NULL the migration
  exists to remove — invisible until the imported adventure forked.
* The action cap counted a v1 file's turns, and a turn expands into a row per
  saved attempt, so a file inside the cap could write a multiple of it.
* Forking a live node on a borrowed ancestor promoted a sibling on a branch the
  caller never named. It is a branch switch, and now says so.
* Switching attempts left the state, status and memory panels reading the
  previous take: the story does not change length, so nothing keyed on its
  length noticed. Same class as the branch-switch bug this phase already fixed.
* A retry after switching back numbered the new attempt into the middle of the
  group instead of the end.
* The cursor backfill numbered every action in the table once per adventure;
  correlated to the adventure being updated, it is an index lookup instead.
* Renaming a branch answered own_actions=0.

And one behaviour change recorded rather than repaired: script-visible history
and actionCount no longer count blank-text rows. That is the right shape and
there is no reading compatible with both, so plan/14 says so.

409 tests.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015H5qiyiR7gtFQaoDphHZ3g

backend/tests/test_branch_management.py

@@ -222,6 +222,24 @@ def test_a_name_longer_than_the_column_is_refused(client):
     assert _rename(client, forked, "x" * schemas.BRANCH_NAME_MAX).status_code == 200
 
 
+def test_a_rename_hands_back_the_row_the_listing_would_give(client):
+    """Renaming a branch does not change how many turns are on it.
+
+    `own_actions` was hard-coded to 0 in this response, which only stayed
+    invisible because the panel throws the body away and refetches. Anything
+    that trusted the reply would draw a branch that had just lost its turns.
+    """
+    root, forked = _forked(client)
+    listed = {b["id"]: b for b in _branches(client)}
+
+    renamed = _rename(client, forked, "the cellar").json()
+
+    assert renamed["own_actions"] == listed[forked]["own_actions"]
+    assert renamed["own_actions"] > 0, "the fixture put turns on this branch"
+    assert renamed["depth"] == listed[forked]["depth"]
+    assert renamed["is_head"] == listed[forked]["is_head"]
+
+
 def test_naming_a_branch_of_another_adventure_is_a_404(client):
     root, forked = _forked(client)
     db = SessionLocal()