ledger: sprint-knowledge-center COMPLETE — PR #3 opened; loop closed

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/agents/LEDGER.md

@@ -146,6 +146,7 @@ _(Maestro appends one line per completed iteration: `<date> · <task ids done>
 - 2026-07-08 · **iteration 1/24** · done: M-03, L-20 (`4b0f0c8` audio engine), L-11 (`7b669f8` piano tab LIVE), D-20 (`96dda6a` Knowledge Center concept), C-20 (`793e60a` lick/level schema, smoke 787) — Critic PASS all four, zero returns · findings folded into the board: D-21 lock += `voicings.js` export-only (GUITAR_SHAPES private); L-22 deps += P-21; P-21 serialized behind P-20 (`jazz/**` overlap); filed L-23 (pre-existing `getGuitarVoicings` rootStr fret-label bug, found by L-20); D-20 discovered ExplorePanel + EducationPanel are ORPHANED (never mounted) → retirement backlogged; famous-progressions level-filter exemption recorded · next ready (file-disjoint): D-21 ‖ P-20 ‖ D-22 (D-22 may build against the SCHEMA fixture until P-21 lands)
 - 2026-07-08 · **iteration 2/24** · done: D-22 (`44d9c4f` LickCard), D-21 (`3c903ad` VoicingBrowser — returned once: rootless voicings badged lowest voice as "R", one-line rootPc fix, PASS on re-gate), P-20 (`c08b334` — returned once: 3 caption theory misstatements, string fixes, PASS on re-gate; KB 56 progs/112 plays, all jazz/gospel/rnb progressions level-tagged) · incident: both first-round gates stalled on API watchdog (600s) twice for P-20 — fresh critic instances completed them; one cron fire absorbed into gate completion · Critic gate quality note: both returns were real musical defects caught before commit
 - 2026-07-08 · **iteration 4/24** · done: P-21 (`6ea1089` 12 licks blues/jazz/funk — every note pitch-verified), P-22 (`9e2567c` jazz piano cell, KB's first authored piano pack, 126 plays — returned once: 6 prose voice-leading overclaims on fifths-apart dominants, fixed + arithmetic-verified, PASS on re-gate), L-22 (`78706ce` **Knowledge Center shell LIVE** — 4-section dock, level filter, licks grid; App.jsx +1 line, audio contract grep-clean) · filed: C-22 (validator span check), L-24 scoped out of P-22 (authored-pack rendering) · promoted: L-24, C-22, P-23 · iteration 5 batch already in flight: D-23 ‖ D-24 ‖ P-24
+- 2026-07-09 · **iteration 8/24 — SPRINT `sprint-knowledge-center` COMPLETE** · done: C-21 (sprint-end sweep — build/validator/smoke all green on 72c6d45; full-App SSR renders; authored vs computed piano paths both proven; zero dead imports; audio contract +1 line since seed) · **PR #3 opened: https://github.com/whattheflat/JamBuddy/pull/3** (supersedes PR #2 — main hadn't absorbed it) · all 21 sprint tasks done, 4 returned-then-fixed by the gate, 0 unresolved · loop cron deleted after 8 of 24 budgeted iterations (board empty) · remaining backlog: EducationPanel retirement, FAMOUS_PROGRESSIONS level tags, smoke drift guards, pianoVoicing rootPc, negative-fret unify, L-12, bass renderer
 - 2026-07-09 · **iterations 6–7/24** · done: L-25 (`e24aa4b` instrument-scoped modal tabs), C-22 (`b4e8f12` validator hand-span rule, smoke 799), P-23 (`564a9e0` gospel piano cell, 140 plays — returned once: one improv-row scale claim false for vi7/iii7, split into exact rows, PASS re-gate; 39/40 first-pass claims held), L-24 (`2165bb5` authored piano packs render at stations — implementer agent hung at verification after ~1 h, killed, completion-pass agent audited + finished; Critic PASS with 0 resolver drift) · incidents: P-23 stalled once mid-authoring (resumed from transcript, no loss); L-24 hung silently (diff intact, completed by fresh agent) · backlog: resolveDegree drift guard filed · **board empty except C-21 → sprint-end sweep + PR**
 - 2026-07-08/09 · **iteration 5/24** · done: D-23 (`db397f6` VoicingBrowser show prop + LickCard stack-guard), D-24 (`e2110ae` MiniPiano thumbs crop to voicing span, 266→142 px), P-24 (11 licks rock/country/reggae — KB now **23 licks across 6 styles**, every note pitch-verified) — Critic PASS all three, zero returns · D-24 gate raised a false alarm on the D-21 rootPc fix (its harness bypassed VoicingBrowser; Maestro verified line 297 intact — no regression); hardening idea backlogged (`pianoVoicing` return rootPc) · promoted L-25 · next ready (all file-disjoint): L-24 ‖ L-25 ‖ C-22 ‖ P-23, then C-21 closes the sprint
 - 2026-07-08 · **iteration 3/24** · done: L-21 (`951d544` VoicingBrowser live in ChordDetailModal Guitar/Piano tabs + JamGuide enlarged stations — the "playable voicings per chord" user ask is now end-to-end), L-23 (`f4e0ac6` getGuitarVoicings base-fret fix — 252 movable-shape placements corrected, A-shape C was labeled fret 1 not 3) — Critic PASS both, zero returns this round · follow-ups filed: VoicingBrowser `show` prop (Muse), negative-fret handling inconsistency (Luthier), stale JamGuide header comment · P-21 lock narrowed to the 3 guitar.js files → P-22 now disjoint · next ready (file-disjoint): P-21 ‖ P-22 ‖ L-22 (licks section may land empty-state-first per D-20 doc)