Column resize moves the header but never the body cells

[neo-opus-grace]

Context

Operator report: column drag and resize break in this app. Reproduced locally and traced to a single cause — this repository consumes published neo.mjs@13.1.0, and the two fixes for exactly this defect landed on neo's dev after that release was cut.

No code in this repository is at fault. The app's own view layer is byte-identical to neomjs/neo's copy apart from import paths (GridContainer.mjs 421/421 lines, MainContainer.mjs 63/63, Heuristics.mjs 97/97, Viewport.mjs 139/139, zero substantive diff lines). Filing it here because the app that misbehaves is this one, and the fix has to be received here.

Live latest-open sweep: 0 open issues in this repository at 2026-08-20T12:05:15Z; no equivalent possible. A2A in-flight claim sweep over the latest 30 messages: no overlapping [lane-claim].

The Problem

Measured at ef0390a, neo.mjs@13.1.0 installed, Chrome at 1920×1080, driving /apps/devindex/index.html from this repo's own dev server. One column resized by dragging its right-edge handle 150px:

arm	header width	first-row cell, mid-drag	first-row cell, on drop
published 13.1.0 (as shipped)	60 → 210	60 → 60	60 → 60
the same app against neo dev src/	60 → 210	60 → 210	60 → 210

Only the engine differs between the two arms — same app code, same gesture, same harness, same browser. The gesture always lands (the header always resizes); the body cells never follow on 13.1.0, neither live nor on drop. That is the operator's report exactly.

Symbol probe against the installed package, not inferred from git:

symbol	origin	node_modules/neo.mjs@13.1.0	neo dev src/
refreshColumns	neomjs/neo#17289 — the live-repaint half	0 files	2 files
isMeasuredWidth	neomjs/neo#17327 — width comes from config unless layout owns it	0 files	1 file

refreshColumns is the mechanism: without it a pure width change leaves the mounted column range unchanged, the config never notifies, and the cells keep the geometry that was just replaced.

Timeline. v13.1.0 was cut 2026-07-03. neomjs/neo#17289 landed d41f68520e on 2026-08-17; neomjs/neo#17327 landed 3085d62855 on 2026-08-18. Both are ancestors of neo's dev and of neither main, so no published release carries them.

The Architectural Reality

• package.json pins "neo.mjs": "^13.1.0" — a caret range, so a 13.2.0 publish satisfies it with no manifest edit
• apps/devindex/view/home/GridContainer.mjs — ~37 columns, component-backed cells; the shape is unusual but not implicated
• The engine surfaces are grid/header/Toolbar.mjs (isMeasuredWidth, passSizeToBody) and grid/Body.mjs (refreshColumns), both inside node_modules/neo.mjs

The Fix

Nothing changes in this repository's source. Receive a neo.mjs release that carries both fixes:

1. v13.2.0 (or later) is published from neo's dev
2. A fresh install / lockfile refresh here picks it up under the existing ^13.1.0 range
3. Re-run the reproduction above and confirm the cells track in both arms

neomjs/neo#17401 — component cells keeping their first record's content across a scroll — merged to neo dev today and affects this same grid. It should ride the same release rather than a second one.

Acceptance Criteria

• The installed neo.mjs reports a version whose src/ contains both refreshColumns and isMeasuredWidth
• Dragging a column's resize handle updates the body cell widths during the drag, not only on drop
• On drop, the following columns' positions settle against the new width
• The reproduction table above is re-run at the upgraded version and the 13.1.0 row is the only one showing stale cells
• Scrolling after the upgrade shows component-backed cells (User, Impact, Top Repo, Location) following their record — the Component cells keep their first record's content when rows recycle neo#17401 half

Out of Scope

• Removing apps/devindex from neomjs/neo — tracked on The Data Sync Pipeline uses git history as a state database — 95.6% of neo's 3.8 GiB pack is one hourly-rewritten file neo#17238, and gated on this ticket closing
• A frozen opt-in cursor lets stale stars reverse a completed opt-out #9 (frozen opt-in cursor) — same app, unrelated mechanism
• Any change to this repo's grid or view code; there is no defect there to fix

Avoided Traps

Two measurement traps cost real time here; inherit them rather than re-paying.

1. A fresh clone renders zero grid rows, and it is not a bug. npm install does not build the themes. Without dist/development/css/** the stylesheets 404, the grid body computes to height: 0, and row virtualization renders no rows — while the footer still reports Visible Rows: 50,000, which reads exactly like a data-layer fault. Build first:
   node ./node_modules/neo.mjs/buildScripts/build/themes.mjs -f -n -e dev -t all
   (npm run build-themes prompts interactively and cannot be scripted as-is.)
2. The resize handle is injected on hover. A drag started without first hovering the header button's right edge arms nothing and silently does a column reorder instead. Hover, confirm a .neo-resizable exists, then press.

Related

• Column resize updates header widths but no longer the grid cells neo#17289 — header→cell width sync on resize (the live-repaint half)
• Cells keep stale geometry when a column resize is dropped neo#17327 — a column's width comes from its config unless layout owns it
• Component cells keep their first record's content when rows recycle neo#17401 — component cells must follow their record across a scroll
• Header buttons stay at their pre-drag positions for the whole resize drag neo#17409 — the original investigation, closed as not-a-defect in that repository; this ticket is its real home
• The Data Sync Pipeline uses git history as a state database — 95.6% of neo's 3.8 GiB pack is one hourly-rewritten file neo#17238 — the epic whose terminal step is blocked by this

Origin Session ID: 3e4f33e0-fb23-4a61-a2a0-7f396950f3d6

Handoff Retrieval Hints: query_raw_memories("devindex column resize published 13.1.0 refreshColumns"). Commit anchors: neo d41f68520e, 3085d62855; this repo at ef0390a.