description box: right border is offset for CJK / wide characters (padded by code units, not display width)

Start in src/ui/utils.ts at line 37 and read renderBox() near line 15, then compare the description padding with truncateText() and the existing wcswidth() helper. Reproduce with the CJK, wide-star, and ZWJ descriptions from the issue. Done means every description row occupies the configured display width and the right border aligns with the top border.

Describe the bug

The suggestion description box (the right-hand box) is padded with String.prototype.padEnd, which counts UTF-16 code units, while renderBox() draws the border assuming the row occupies exactly width terminal columns. Whenever a description contains characters whose display width differs from their code-unit length — CJK text, BMP-wide emoji (e.g. U+2B50), ZWJ emoji sequences — the right border is offset: pushed out for wide characters, pulled in for ZWJ sequences.

The suggestion name box is unaffected, because truncateText() already pads with wcPadEnd()/wcswidth().

To Reproduce

1. Add a local spec via specs.path:

~/.config/inshellisense/rc.toml

[specs]
path = ["/Users/<you>/.config/inshellisense/specs"]

~/.config/inshellisense/specs/index.js

const specs = ["opencode"];
const diffVersionedCompletions = [];
export { specs as default, diffVersionedCompletions };

~/.config/inshellisense/specs/opencode.js

export default {
  name: "opencode",
  description: "OpenCode command line interface",
  subcommands: [
    { name: ["upgrade", "update"], description: "⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐" },
    { name: "auth", description: "以一条消息运行 OpenCode" },
  ],
};

2. Start is and type opencode up

Actual behaviour

The description box's right border does not line up with the top border. With 10 × U+2B50 the row is padded to 38 columns instead of 28:

Expected behaviour

Every row is padded to width display columns, so the box borders stay aligned, exactly like the name box.

Root cause

src/ui/utils.ts:37

return truncatedLines.map((line) => line.padEnd(width));

padEnd pads to width code units, but renderBox() (line 15) emits "│" + row + "│" assuming row is width columns wide. Measured with the repo's own wcswidth() (width = 28, i.e. descriptionWidth - borderWidth):

Note that astral emoji happen to match (2 code units = 2 columns), which is why the bug can look like it only affects CJK; ZWJ sequences fail in the opposite direction.

Suggested fix

Use the display-width helper that already exists in the same file and is already used by truncateText():

return truncatedLines.map((line) => wcPadEnd(line, width));

ASCII descriptions are unaffected (wcswidth(text) === text.length for them). PR to follow.

Environment

• inshellisense 0.0.4 (Homebrew), is --version → 0.0.4
• macOS 27.0 (26A428)
• zsh
• VS Code integrated terminal

Related: #175, #302