unstable/cli: help tables misalign when the left column contains wide or combining grapheme #7557

What version of Effect is running?

4.0.0-rc.112

What steps can reproduce the bug?

// repro.mjs
import { NodeRuntime, NodeServices } from '@effect/platform-node';
import { Effect } from 'effect';
import { Command, Flag } from 'effect/unstable/cli';

const demo = Command.make('demo', {
  file: Flag.string('ファイル').pipe(Flag.withDescription('The file to read.')),
  verbose: Flag.boolean('verbose').pipe(Flag.withDescription('Say more.')),
});

NodeRuntime.runMain(
  Command.run(demo, { version: '0.0.0' }).pipe(Effect.provide(NodeServices.layer)),
);

node repro.mjs --help

What is the expected behavior?

Both flag descriptions start in the same column, as they do for ASCII-only flag names.

What do you see instead?

FLAGS
  --ファイル string    The file to read.
  --verbose        Say more.

The first description sits 4 cells further right. visualLength in CliOutput.ts is stripAnsi(text).length, i.e. UTF-16 code units, but a terminal draws cells: each CJK character is 1 unit and 2 cells, so the column is under-padded by one cell per character. The same measurement over-pads for combining marks (e + U+0301 is 2 units, 1 cell) and miscounts zero-width characters, so any localized command name, metavar, or alias breaks the table.

Additional information

Fixing this means the formatter needs a real display-width function (wide via East Asian Wide/Fullwidth and Emoji_Presentation, zero for combining marks and zero-width controls, segmented by grapheme). No dependency is required — Intl.Segmenter plus Unicode property escapes cover it in every supported runtime. Once that function exists internally, please consider exporting it: a custom CliOutput.Formatter or prompt renderer has to measure text by exactly the same rules as the built-in help to align with it, and today the only options are reimplementing the logic or pulling string-width.