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now stays; a summary that genuinely ends there is still withdrawn.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/app/attempts.py

@@ -150,7 +150,17 @@ def add_attempt(
     replacement.branch_id = previous.branch_id
     replacement.depth = previous.depth
     replacement.live = True
-    replacement.variant_index = previous.variant_index + 1
+    # The end of the group, not one past `previous` — which is only the same
+    # thing when `previous` is the newest take. Switch a three-take turn back to
+    # take 1 and retry, and `previous.variant_index + 1` collides with take 2;
+    # `renumber` then breaks the tie by id and files the new attempt *between*
+    # takes 2 and 3, so the pager walks the takes in an order they were not made
+    # in. `group` is oldest-first, and `replacement` is not in it yet.
+    siblings = group(db, previous)
+    replacement.variant_index = 1 + max(
+        (s.variant_index for s in siblings if s.variant_index is not None),
+        default=previous.variant_index or 0,
+    )
     previous.live = False
     # The replacement was assembled with a fresh snapshot, so the prompt for
     # this turn is now the one it carries; the superseded attempt keeps only