Three things that only showed on screen

Grey letters ran down the bar while dragging a column edge. The editor marks
the column under the pointer by putting a small div in each of its cells;
drawn along the cell's right edge, that absolutely positioned child sent
Chromium down another painting path and the cell's own text came out a second
time, squeezed into the two pixels under the bar, one letter to a line. It
appeared with the bar and went with it, which named the culprit -- measured,
there was no text there at all, only three empty markers, and a forced repaint
did not clear it. The marker is display:none now and only says which cells the
column is made of; the line is an inset shadow on those cells, matched with
:has(). Two suspects were tried and reverted first: the table as its own paint
region, and separate borders. Neither changed anything, so neither stayed.

Opening a note flashed a long narrow page. The drawing stage starts at the
canonical page, 1600px tall, and the measurement that fits it to the pane ran
as an ordinary effect -- a frame too late. useLayoutEffect runs between the DOM
being built and the browser painting it, which is exactly the gap that flash
lived in. The test samples the sheet's height every frame across a note switch,
because one frame is all it was.

The mark above a note did not stand in the same column as the tools below it.
Vertically it was already exact -- measured, symbol centre 20, cap centre 20 --
but it began six pixels right of the first tool, and the title thirty. The
mark's box is only as wide as the mark now, so the mark lands on that column,
and the title follows nine pixels closer.

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

readme.md

@@ -458,7 +458,7 @@ docker compose -f docker-compose.dev.yml up -d --build   # must be running
 | Suite | Checks | What it holds down |
 | --- | --- | --- |
 | `admin` | 15 | no sign-up anywhere; `/api/admin/*` refused for non-admins even when called directly |
-| `editor` | 36 | tables and their right-click menu, task lists, note links, backlinks — and that each survives a reload |
+| `editor` | 37 | tables and their right-click menu, task lists, note links, backlinks — and that each survives a reload |
 | `search-attachments` | 12 | body-only matches, ranking, umlauts; images as blob URLs, not inline bytes |
 | `history` | 10 | a large deletion is snapshotted, restoring works, restoring is itself undoable |
 | `drawing` | 18 | strokes survive the poller, match across four viewport widths, and stay on the page they were drawn on |
@@ -469,7 +469,7 @@ docker compose -f docker-compose.dev.yml up -d --build   # must be running
 | `organise` | 75 | a hand-made order survives a search; a new note lands on top and a deleted one takes only itself; one line goes under another and stays there |
 | `chapters` | 60 | a filed note stays filed across a sync; a chapter is dragged among its neighbours *and* takes what is dropped in it; its own order is set in its own dialog |
 | `offline` | 17 | a cold page load with the network off still opens notes and searches them — and a note made, written and drawn on offline arrives whole once there is a connection |
-| `tables` | 8 | a long table is broken between its rows, with none left lying across the gap, and no page furniture reaches the stored note |
+| `tables` | 11 | a long table is broken between its rows, with none left lying across the gap, no page furniture reaches the stored note, and the column edge being dragged is drawn on the cell rather than in it |
 | `sync` | 7 | a PDF written on one device — document, drawing and pinned notes — reaches a second one, which can find it by its contents without opening it |
 
 Each suite creates a throwaway account through the admin API and deletes it
@@ -533,6 +533,14 @@ sheet's margin, rather than an unexplained void.
 The sheet used to appear only once you started drawing, which made the writing
 mode look like text floating in an empty pane.
 
+**The sheet is measured before the first paint**, not after. It starts at the
+canonical page the drawing lives in — 1200 × 1600 — and is fitted to the pane by
+a measurement; as an ordinary effect that ran a frame late, so every note opened
+by drawing one frame of a sheet sixteen hundred pixels tall and then righting
+itself. A `useLayoutEffect` runs between the DOM being built and the browser
+painting it, which is exactly the gap that flash lived in. A test samples the
+sheet's height every frame across a note switch, because one frame is all it was.
+
 **Pages are counted, not stored.** The toolbar says *Page 2 of 4* in the same
 words the PDF reader uses. A page is the same 3:4 the canvas uses, so "page 2"
 means the same thing writing or drawing. The note itself stays one continuous
@@ -571,6 +579,19 @@ Anything else too tall to fit anywhere — a full-page image — is left where i
 and runs over the gap: moving it down only puts the same problem one sheet
 further on.
 
+**The column edge you drag is drawn on the cell, not in it.** The editor marks
+the column under the pointer by putting a small div in each of its cells, and the
+obvious thing to do is position that div along the cell's right edge. It works,
+and it paints grey letters down the bar: an absolutely positioned child inside a
+cell of a `border-collapse: collapse` table sends Chromium down another painting
+path, and the cell's own text comes out a second time, squeezed into the two
+pixels under the bar, one letter to a line. It appeared with the bar and went
+with it — which named the culprit, since the DOM at that spot held nothing but
+three empty markers. The marker is `display: none` now and only says which cells
+the column is made of; the line is an inset shadow on those cells, matched with
+`:has()`. Nothing is positioned, so nothing paints twice, and the line looks the
+same — continuous down the column, because each cell carries its own piece.
+
 Two details that are easy to get wrong and were:
 
 - **The spacer's height is not the distance the text moves.** Margins that used