fix(match): index collapsed loop forms — real 12-bar blues now matches its KB entry (task L-60, 1/2)

buildLoopIndex additionally indexes each progression's collapsed form
(adjacent (degree,suffix) dedup + wrap), appended after raw entries so
every prior matcher winner is preserved except the enumerated
country-145 self-attribution. Repairs a pre-existing LIVE-detection
bug: a real 12-bar or 8-bar blues stream collapses to fewer names than
the raw KB degrees, so it matched NOTHING and the Jam Guide sat empty.
JamGuide reads authored plays through the collapsed station's
sourceIndex (all four guitar/piano/bass paths). Adds seedableLoop +
the round-trip roulette pool (smoke sweep: 4 failures / pool 52).
theory.js canonicalize exported. Critic PASS (fix-(a) additivity
proven registry-wide; pool reproduced from the spec; bass sourceIndex
station 5 -> raw 10 hand-checked).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/design/one-screen.md

@@ -506,8 +506,10 @@ flow below `xl` (JamGuide reorders its own children with responsive classes or
 conditional order — no duplicate mounts). The rail **unbounds** below `xl`
 (the max-h/overflow classes are `xl:`-prefixed) and lays out at natural height
 in page flow — a nested scroller inside a scrolling page is a trap on touch.
-Cell wrap at ~576px interior: guitar 5/line, piano two-octave cells alone —
-same behaviour the D-41 gate already verified for the band. The instrument
+Cell wrap at ~576px interior: guitar 5/line, piano cells **pair** (a 284px
+two-octave + a 160px one-octave = 452, or two two-octaves at the 576 boundary) —
+the same margin-hardened pairing D-51 verified for the bounded column (§4),
+with more room here, not the "cells ride alone" of the narrower bounded width. The instrument
 selector never moves: it lives in the controls bar, global, above everything
 at every width.