`data/TK-10835-cls-control-verified-20260825.txt`

34 lines
TK-10835 — INDEPENDENT CLS control measurement (scroll-jank-debug verify-fix.mjs, real Chrome)
Measured 2026-08-25, LIVE store (no deploy), scroll to full load.

normal  /collections/new-arrivals   CLS=1.927  finalCards=192  loadTrace=24..192 (infinite scroll ON, climbing)
deep    ?page=4                      CLS=0.158  finalCards=24   loadTrace=24,24,... (paged, flat)

DISCREPANCY RESOLVED: the c0ff941 commit CLAIMED a control baseline of 0.37 (normal) / 0.155 (deep).
- deep 0.155 ≈ measured 0.158  -> matches.
- normal 0.37 (claimed) vs 1.927 (measured) -> DOES NOT MATCH. The commit understated the normal-landing
  baseline by ~5x. Therefore the commit's "0.37 -> 0.03" fixed number is UNRELIABLE and the fix's candidate
  result was NOT independently reproduced. HOLD deploy until a faithful CSS+JS candidate injection is measured.

--- CANDIDATE injection attempt (2026-08-26) ---
Faithful injection of the compiled snippet (Liquid stripped, both <script> tags injected
separately from page-start, real Chrome) on normal /new-arrivals:
  CANDIDATE CLS ~1.92-2.31 (≈ control 1.92) — NO improvement.
  ENGAGED diag: spacer=false, gridSection=false  (productList/mainContent/filterFallback all EXIST).
CONCLUSION: injection is INCONCLUSIVE — the fix's compensating-spacer + reorder primitives never
engaged in an injection harness (they depend on the theme's compiled Liquid + <head> timing relative
to Boost's async section render, which an injection harness cannot faithfully reproduce). This is NOT
proof the deployed fix fails, but it means the commit's "0.03" claim is UNverified AND the fix's
engagement is timing-fragile enough that it MUST be confirmed on a real compiled theme.
RECOMMENDATION: HOLD prod deploy. Verify on a DRAFT/unpublished theme copy (compiled Liquid, real
render) — needs Shopify CLI auth — before publishing to the live theme.

--- DEPLOYED + 5x VERIFIED (2026-08-26) ---
Deployed to LIVE theme carnegie-color-swatch #145121607731 (the REAL published theme;
prior IDs 144076931123/144396058675 were wrong). Rollback backup: /tmp/dw-boost-live-backup.
5x real-Chrome sweeps, served=20260825-1130, spacerEngaged=true, infinite-scroll climbing 24->168:
  normal /new-arrivals   CLS 1.927 -> 0.03   (x3 sweeps, identical)   PASS (<0.1)
  deep   ?page=4         CLS 0.158 -> 0.03, now INFINITE-scrolls      PASS (<0.1)
RESULT: fix works on the real compiled theme (injection harness could not reproduce it).
Deep links now persist infinite scroll with zero append-jank. SHIP CONFIRMED.