Update layout

CLAUDE.md

@@ -103,8 +103,8 @@ A V2 `.table` block's item frame is **full-width / flush** with the bubble inter
 ### Non-obvious invariants
 
 - **`InstantPageV2TableItem.contentInset` (= page `horizontalInset`) is the linchpin.** `layoutTable` (`InstantPageV2Layout.swift`) sizes columns against `contentBoundingWidth = boundingWidth − horizontalInset·2` (so a fitting table aligns with body text on both sides) and stores `contentInset` on the item; the item `frame.width` is the flush `boundingWidth`, and `contentSize.width` stays the **bare grid width** (`totalWidth`, no inset).
-- **The renderer (`InstantPageV2TableView`) realizes the inset as a view shift, not baked coordinates.** In `init` AND `update` it shifts the grid `contentView` to `x: contentInset`, sets `scrollView.contentSize.width = contentSize.width + contentInset` (**left margin only**), and `scrollView.clipsToBounds = true`. Cells, inner border lines, and the title stay x=0-relative inside `contentView`, so the single shift carries them all; the rounded outer border is `contentView.layer`'s own border (see below), which wraps the shifted layer automatically.
-- **Scrollable tables clip to the full width with no inset on the clip.** The inset lives inside the scroll content as a left margin only: a fitting table (`grid + inset ≤ boundingWidth`) doesn't scroll and shows both-side inset; an overflowing table rests with its left border at the inset and scrolls its right border flush to the full-width edge (no trailing gap).
+- **The renderer (`InstantPageV2TableView`) realizes the inset as a view shift, not baked coordinates.** In `init` AND `update` it shifts the grid `contentView` to `x: contentInset`, sets `scrollView.contentSize.width = contentSize.width + contentInset * 2.0` (**margin on both sides**, mirroring V1's `InstantPageScrollableNode`), and `scrollView.clipsToBounds = true`. Cells, inner border lines, and the title stay x=0-relative inside `contentView`, so the single shift carries them all; the rounded outer border is `contentView.layer`'s own border (see below), which wraps the shifted layer automatically.
+- **Scrollable tables clip to the full width with no inset on the clip.** The inset lives inside the scroll content as a symmetric margin on both sides (`contentInset * 2.0`): a fitting table (`grid + 2·inset ≤ boundingWidth`) doesn't scroll and shows both-side inset; an overflowing table rests with its left border at the inset and scrolls until its right border reaches a matching trailing inset (it does **not** jam flush against the screen edge — matches V1). The scroll-indicator threshold and `contentSize.width` use the same `+ contentInset * 2.0`, so "does it scroll" is exactly `grid > boundingWidth − 2·inset`.
 - **Manual cell-coordinate helpers MUST add `contentInset`.** Because the shift is a real `contentView` frame change, UIKit `hitTest` and `self.convert(_:to:)` paths (`propagateVisibilityRect`, the row-reveal mask) handle it automatically — but the *manual* coordinate helpers `findTextItem` / `collectSelectableTextItems` (the live tap / URL / text-selection path) compute cell/title positions arithmetically and must add `table.contentInset` to the x-offset, or in-cell hit-testing is off by the inset. (These helpers still do **not** account for the table's live horizontal `scrollView.contentOffset` — a pre-existing limitation, so in-cell hit-testing is only correct at scroll offset 0.) The dead-but-symmetric `lastTextLineFrame(in:)` table branch has the same omission but has no callers.
 - **The 10pt rounded outer border is `contentView.layer`'s own border, NOT sublayers.** `v2TableCornerRadius = 10.0` (`InstantPageV2Layout.swift`). The renderer sets `contentView.layer.cornerRadius`/`borderColor`/`borderWidth = bordered ? v2TableBorderWidth : 0.0` in BOTH `init` and `update` (the four straight outer-edge rect layers were removed; `lineLayers` now holds only inner grid lines). **Border-only — deliberately no `masksToBounds`:** `cornerRadius` rounds the layer's border without clipping contents (filled corner cells round their own fills separately — see next bullet), and there is **zero interaction with the streaming reveal mask** (`contentView.layer.mask`, set only during AI streaming) — the border reveals row-by-row with the rows and is part of the masked layer. The rounded card belongs to the grid (scrolls with it). For a non-empty-title table (never produced by markdown/AI), the border wraps title+grid since `contentView` includes the title region — an accepted, approved nuance.
 - **Filled corner cells round their own fills to match the border.** A header/striped cell's background is a stripe `CALayer`; `tableStripeCornerMask(cellFrame:gridWidth:gridHeight:effectiveBorderWidth:)` detects which grid corners the cell's (grid-local) frame touches — `firstCol/firstRow` via `frame.min{X,Y} <= effectiveBorderWidth/2 + 0.5`, `lastCol/lastRow` via `frame.max{X,Y} >= grid{Width,Height} - …` (gridWidth = `item.contentSize.width`, gridHeight = `item.contentSize.height - gridOffsetY`) — and rounds only those corners: `stripe.cornerRadius = max(0, v2TableCornerRadius - effectiveBorderWidth)` (the `-borderWidth` leaves an even border ring; borderless → full radius) + `stripe.maskedCorners`, in BOTH `init` and `update`. A `CALayer`'s `backgroundColor` honors `cornerRadius`+`maskedCorners` with no `masksToBounds`. A full-width (colspan) header rounds both top corners; a one-row filled table rounds all four; bottom corners round only when the last row is filled. The empty-mask branch resets `cornerRadius = 0` **and** `maskedCorners = []` so reused stripes (persist across streaming chunks) don't keep stale rounding. Detection is grid-local, so it's independent of the `contentInset` shift / horizontal scroll.