fix(web): close a run at the line end and count columns correctly

Eight findings, each terminal case verified in a real terminal first:

`\x1b[32mdone\rok\x1b[0m` then `plain` shows `okne` green and `plain` in the
DEFAULT color. The replay returned the last written cell's state, so a reset
landing after the final write vanished from both the text and the returned
state — and every build tool writes exactly that shape, so the color leaked
onto all later output. The replay now converges to the state the scan ended
in, which is also what it hands to the next line.

`abcd\b\x1b[1K|` shows `   |`: CSI 1K erases THROUGH the cursor column, and
the loop stopped before it. The erase mode also reads only the first
parameter now, since a terminal treats `1;2K` exactly as `1K`.

`éx\rYZ` shows `YZ`: a combining mark takes no column, so it attaches
to the cell already written instead of advancing the cursor and leaving the
`x` standing.

`中x\rA` shows `A x`: overwriting a wide character's lead cell leaves its
spacer as a blank rather than closing the gap, which would shift everything
after it one column left.

The banner lost its span when the gutter became padding — a plain block child
only reaches the content box, so the reserved column was painted in the body
color and the card's top-left radius drawn in it. Invisible in the light
theme, where banner and body share a token; visible in the dark one. The
header now pulls back across the gutter and re-insets by the same amount.

The replay trigger matches the same CSI shape the parser accepts, so a form
like `\x1b[1;2K` can no longer skip its own erase, and `replayLine`'s JSDoc
documents its new parameter and returned pair.

Docs: four places still described the dot as sitting left of the card surface,
which stopped being true when the gutter became the card's own padding, and
two fixture comments still referenced the exit marker that was deliberately
removed.

packages/client/ui-primitives/README.md

@@ -10,7 +10,7 @@ Pure React atoms (zero cordis): StateDot, ic_ds_* icons, Button/Pill/Menu/Modal/
 
 ## Terminal output
 
-`TerminalBlock` renders a shell command as a terminal surface: one prompt row per line of the command (the shortened `cwd` label on the first row only, since the view knows one working directory and a `cd` moves later lines elsewhere, then that line), the command's output, a status pill for a non-zero exit code or a terminating signal, and a copy control that writes the raw `output` prop. A run-state `StateDot` marks the call once, on the first row, out of flow in a gutter to the left of the card surface. It reaches three of `StateDot`'s states — the chase while `running`, red for the same exit status that renders the pill, green otherwise — so a card states whether its command is still running rather than leaving that to be inferred from the presence of output; it carries one visually hidden text label because `StateDot` is `aria-hidden`. One dot regardless of line count is deliberate: the exit status is the whole call's, so a dot per line would claim a per-line outcome the view does not carry. Command text is `white-space: pre`, so repeated spaces, tabs, and an indented continuation render verbatim while the row stays single-line and ellipsizes. ANSI escape sequences are parsed with the `anser` runtime dependency into React spans; carriage return and backspace replay into a per-line column buffer before inert controls are stripped, since both only move the cursor (so `100%` + CR + `OK` shows `OK0%`), with SGR state stamped per column as a terminal stores it per cell; basic-16 foreground colors map onto `--dsw-*` tokens, while 256-palette and truecolor values pass through as literal rgb. Output keeps `white-space: pre` with horizontal scrolling, so column-aligned output holds its alignment instead of soft-wrapping, and collapses to a head slice plus a tail slice past `maxLines` (default 16, the TUI transcript's split arithmetic) behind an expand button. Rationale: [the web terminal card note](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md).
+`TerminalBlock` renders a shell command as a terminal surface: one prompt row per line of the command (the shortened `cwd` label on the first row only, since the view knows one working directory and a `cd` moves later lines elsewhere, then that line), the command's output, a status pill for a non-zero exit code or a terminating signal, and a copy control that writes the raw `output` prop. A run-state `StateDot` marks the call once, on the first row, out of flow in a gutter the card reserves as its own left padding, so the dot sits inside the card box yet left of the prompt text. It reaches three of `StateDot`'s states — the chase while `running`, red for the same exit status that renders the pill, green otherwise — so a card states whether its command is still running rather than leaving that to be inferred from the presence of output; it carries one visually hidden text label because `StateDot` is `aria-hidden`. One dot regardless of line count is deliberate: the exit status is the whole call's, so a dot per line would claim a per-line outcome the view does not carry. Command text is `white-space: pre`, so repeated spaces, tabs, and an indented continuation render verbatim while the row stays single-line and ellipsizes. ANSI escape sequences are parsed with the `anser` runtime dependency into React spans; carriage return and backspace replay into a per-line column buffer before inert controls are stripped, since both only move the cursor (so `100%` + CR + `OK` shows `OK0%`), with SGR state stamped per column as a terminal stores it per cell; basic-16 foreground colors map onto `--dsw-*` tokens, while 256-palette and truecolor values pass through as literal rgb. Output keeps `white-space: pre` with horizontal scrolling, so column-aligned output holds its alignment instead of soft-wrapping, and collapses to a head slice plus a tail slice past `maxLines` (default 16, the TUI transcript's split arithmetic) behind an expand button. Rationale: [the web terminal card note](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md).
 
 ## Model Experience