fix: ship implementation libraries as dependencies, not peers (Issue epam/ai-dial-chat#8719)

[PolinaGurinovich97]

Description and UI changes:

No UI changes — packaging only. No component, style or runtime behaviour is
touched.

react and react-dom are now the only required peers of this package.

An embedding host audited what it has to declare in its own package.json to
render a DIAL chat column and found 25 packages it never imports, several of
them ours. This is the ui kit's half of that report.

Implementation libraries the kit renders with → dependencies

Package	Where it is reachable from
@floating-ui/react	eagerly from every entry point (21 source files)
classnames	eagerly from every entry point (37 source files)
@tabler/icons-react	eagerly from every entry point (119 source files)

These are implementation detail of this package — a host does not name them, it
just renders a Button. Requiring them as peers meant every consuming
application carried three entries it never imported, and a missing one only
showed up as an install warning.

Editor packages → optional peers

@monaco-editor/react, monaco-editor and @uiw/react-md-editor are
reachable only behind the Lazy* wrappers the ./editors subpath exports, so a
consumer that never mounts an editor has no use for them. As optional peers,
npm install stays quiet without them and the kit reaches for them only when a
lazy editor actually mounts.

They deliberately stay peers rather than becoming dependencies: Monaco is
large, and npm cannot scope a dependency to one entry point, so making them
dependencies would push the whole editor stack into every consumer that only
wants a button.

@uiw/react-markdown-preview → dropped

Nothing in this package imports it, and @uiw/react-md-editor already depends
on it, so requiring it of the host was asking for something that could not be
missing in the first place.

What a consumer does

Nothing, unless they want to. An existing package.json keeps working
unchanged — the point is that four to six entries can now be deleted from it.

Issues:

• Issue Add required packages as deps to new lib packages ai-dial-chat#8719

Verification:

npm run verify:distribution — all 10 fixtures pass end-to-end, the export
surface matches its baseline (342 exports), root/./grid/./file-manager/
./editors keep export parity in ESM and CJS, and all 14 exports targets are
present in the pack.

Two of those fixtures install the editor packages (consumer-markdown-editor,
consumer-json-editor) and two install none of them (consumer-esm,
consumer-mixed-grid-editors-subpath) — the latter importing from ./editors
and still building. That is what makes the optional declaration accurate rather
than a required peer with its warning suppressed.

Also green: typecheck, lint:check, test:run (183 files, 2493 tests),
build, format.

Checklist:

• the pull request name complies with Conventional Commits
• the pull request name ends with (Issue #<TICKET_ID>) (comma-separated list of issues) — the issue lives in epam/ai-dial-chat, so the title carries the cross-repository reference

🤖 Generated with Claude Code

[stropalov]

Moving @floating-ui/react, @tabler/icons-react, and classnames to dependencies also changes the build output: vite.config.ts derives external exclusively from peerDependencies, so these packages are now bundled into ui-kit.
An A/B build of the current chat application confirmed duplicate Tabler modules between ui-kit and the application’s direct dependency. Initial JavaScript increased by 10,425 bytes gzipped, and the number of initial JS chunks grew from 93 to 109. Heavy-module isolation remained intact in the standalone consumer test.
I suggest keeping these packages in dependencies while explicitly preserving their externalization:

const externalDependencyNames = [
  ...Object.keys(peerDependencies),
  '@floating-ui/react',
  '@tabler/icons-react',
  'classnames',
];

const isExternalDependency = (id: string) =>
  externalDependencyNames.some(
    (dependency) => id === dependency || id.startsWith(`${dependency}/`),
  );

This preserves automatic dependency installation while allowing the application’s bundler to deduplicate them against direct imports.