A bundle had one list and a forked adventure has two stories, so export was
emitting every branch's turns interleaved by index — a mangled story rather
than lost data, and unreachable only because forking has no UI yet.
`ai-dnd-adventure-v2` carries the branches, the depth each one left its
parent at, which attempt at every turn is the story, and what each node
left behind. That last one is not decoration: the after-snapshots are what
a branch switch puts back, and a bundle without them imports a tree nobody
can switch inside.
`app/bundle.py` owns both formats and nothing else knows either. The v1
reader stays — those files are already on people's disks — and it is now
the only place a `variants` array exists anywhere.
The rule the module is built on is that a bundle carries what was chosen
and never what is derived. The head branch, the fork points, the live flags
and the anchors are decisions somebody made. The lineage, the head depth,
the legacy `index` and the variant ordinals are computed from those and are
rebuilt on the way in, because a bundle is a text file anybody can edit and
a derived field shipped beside its source is a chance for the file to
disagree with itself where no read would report it.
`index` is the one that stops being academic here. It agreed with `depth`
until SP5, and this is the first writer that has to fill it for a forked
story, where two branches both hold a node at depth 4. It is allocated one
per turn instead: siblings share it, no two coordinates do.
Everything a hand-edited file can get wrong about the shape of a tree is a
400 raised before the adventure row exists, because a half-applied import
is exactly the failure this phase exists to end — a story that goes quiet.
A file wrong about which attempt is live is corrected rather than refused;
that is an invariant of the database, not of the format.
Measured on the 600-action fixture: 587 kB to 911 kB, and all of the
increase is the outcomes at 489 B a node — the coordinates themselves save
57.5 B a node against the old turn-and-variants shape. Twenty forks add
660 B. 4.3% of the import body cap.
381 tests green, 16 of them new in test_bundle_v2.py. No migration, no
vacuum owed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015H5qiyiR7gtFQaoDphHZ3g
Every attempt at a turn is now its own row at the same (branch, depth),
with `live` naming the one the story tells. The JSON repeating group on
`actions.variants` is read one last time, by a migration that writes it
out as the sibling rows it always described, and then goes unread.
The snapshots turn around with it: an action carries the state it left
behind rather than the state it started from, because attempts at one
turn share a starting position and differ exactly in their outcome.
Rolling back is "what the node in front left behind", one lookup on the
path, and it is what undo and retry now both read.
And the memory holdback goes. It existed because retry rewrote a row
under a mark that had already moved past it; a retry writes a sibling
now, and replacing what a coordinate says withdraws what was derived
from it — the same repair undo and delete already made.
The assembled prompt is still stored once per turn: it moves with the
live flag, so a superseded attempt keeps only the few hundred bytes that
were its own. Measured on the 600-action fixture: 700 rows for the same
600-turn story, prompt archive byte-identical at 0.50 MB, index 1.8 kB
and page load 62.7 kB unmoved.
347 tests green. `tests/test_story_tree_baseline.py` and
`tests/test_retry_variants.py` pass unmodified — SP4 was allowed to move
the baseline for the variant-count semantics and did not need to.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017Dvvqn9ZDR4ixeFPHNbww7
