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now stays; a summary that genuinely ends there is still withdrawn.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

plan/14-phase-story-tree.md

@@ -812,6 +812,17 @@ hand-driving *or* the harness and this took the first. The harness remains the t
 would catch a prepend regression without a person in the loop, and jsdom's lack of layout
 means it would not have settled the 5 px question either way.
 
+**One user-visible change nobody asked for, recorded here because a script
+author would otherwise find it by being surprised.** Moving `_history` onto
+`context_history.story_actions` fixed the branch bug it was there to fix, and
+carried a second change with it: `story_actions` drops blank-text rows, which
+`adventure.actions` did not. So a user script's `history` array and
+`info.actionCount` both got shorter for any adventure holding one. It is the
+right shape — a textless row is bookkeeping with no AI Dungeon counterpart, and
+the prompt never included one — but a script that fires "every N actions" now
+fires on different turns. Not compatible with both readings; this is the one
+chosen.
+
 ### SP8 — Drop the legacy columns
 
 Only once the tree is proven live. Migration drops `index`, `variants`, `variant_index`,