Two-lane packing, and the shelves ship with the export

Eric's wall answered the orientation question with a screenshot full
of red: the capacity model assumed one flat stack per opening, so his
spine-out cubes read 200% full. His reviewer's prescription, built to
its acceptance cases: each opening packs a FLAT lane (thinnest axes
against interior height, claiming the widest flat box's width) and a
STANDING lane beside it (boxes on edge against the remaining width;
standing boxes must fit height and depth upright). The largest-
footprint class lies flat, smaller boxes stand, any box's lane is
flippable per-assignment (▬/▮ toggle in the opening view, ✱ marks an
override), and ⚠ now means NO packing fits — not merely "tall stack".
Unmeasured boxes take no lane but keep their honesty tag; dual fill
bars show each lane's budget; a broken opening is never offered by
the suggester. On the real wall: the double-wides and half the cubes
went green (7 games = 13.12" flat + 2.91" standing), and the
remaining warnings mark cubes that genuinely hold 12-16 boxes.
Both reviewer acceptance tests pass verbatim.

And the export gains the humanity Eric asked for: game pages say
where each box lives, containers list their contents, and a shelves
page draws the wall as it physically stands — proportional cells,
zones, descriptions, every opening linking its residents. Publishing
a shelf layout is a choice: --no-shelves keeps the layer out.
"shelves" joins "art" as a reserved slug. 387 tests.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jXZFSTZQKzAC8fqpWSz9g

docs/guide.md

@@ -145,14 +145,24 @@ chains (minis in an insert in a big box live where the big box does). On a
 phone over `--lan`, the opening view docks as a bottom sheet — the
 moving-day loop is search, tap, done.
 
+When you publish with `bggpipe export`, the shelves come too: game pages
+say where each box lives, containers list their contents, and a shelves
+page draws the wall as it physically stands, every opening linking its
+residents. Publishing your shelf layout is a choice — `--no-shelves`
+keeps the whole layer out of the export.
+
 Bulk-load a reviewed plan with `bggpipe shelve --import plan.csv` (columns
 `name,opening`, accepting opening ids or labels) — rejects are reported
 (unknown name, ambiguous copies, unknown opening, doesn't fit, lives
 inside another box), never guessed, and re-imports preserve hand-entered
 notes. `bggpipe dims` reports per-opening capacity, overfull warnings, and
-misfits against your real furniture. Fill bars measure stacked thickness
-against interior height (boxes lying flat); unmeasured boxes are counted
-and shown, never silently assumed to fit.
+misfits against your real furniture. Capacity uses a **two-lane packing
+model**: each opening holds a flat stack (thinnest axes summing against
+interior height, claiming the widest flat box's width) and a standing lane
+beside it (boxes on edge against the remaining width) — the largest boxes
+lie flat, smaller ones stand, and you can flip any box's lane in the
+opening's view. An opening warns only when *no* packing fits. Unmeasured
+boxes are counted and shown, never silently assumed to fit.
 
 ## Shelf-space planning