document the showcase site in CLAUDE.md

[kualta]

Summary

ui/CLAUDE.md described this repo as source-only: the architecture tree listed just src/, and the commands listed only typecheck / lint / check / publish. Nothing mentioned app/ — the Vite showcase that is built by the Dockerfile and deployed live at https://ui.flow.industries.

An agent reading the doc reasonably concluded the showcase did not exist. That produced a Plane epic (UI-9) asking to build a component gallery from scratch, with the stated evidence "the package has no build step and no gallery/storybook (ui/ has only src/ + biome + tsc)". The gallery has existed the whole time and renders 54 component sections.

Changes

• Split the architecture section into the package (src/, published, no build step) and the showcase site (app/, Vite, not published — files: ["src"]).
• Documented the showcase: the three hash-routed pages (#design, #showcases, #components), the Dock that switches them, and the light/dark toggle that flips .dark on documentElement.
• Noted the Dock is hidden sm:flex, so below the sm breakpoint there is no visible page/theme switcher — anything driving the page programmatically should set the hash and .dark directly.
• Added bun run dev / build / preview to the commands block.
• Noted that components are exported through the ./components subpath, not the root barrel (src/index.ts only exports cn and useIsMobile), so src/components/ui/index.ts is the list to read.
• Added the expectation that a new component also gets a showcase section.
• Corrected the component count from "50+" to "60+" (65 files today).

Testing

Documentation only — no code changed.

• Verified every claim against the repo: app/App.tsx (~3.5k lines) imports 57 of 65 components; the Dock's three hashes and theme toggle are at app/App.tsx:2722; package.json has files: ["src"] and the dev/build/preview scripts.
• Verified against the live site: https://ui.flow.industries/#components renders 54 component sections, #showcases renders the composed demos.

Plane UI-9 — https://plane.flow.industries/flow/browse/UI-9 (rescoped to match reality: visual-regression + axe gates over the existing showcase, rather than building a gallery).