Register @import-ed CSS files as Metro dependencies so token-only edits hot reload

[fendyk]

CSS files that global.css (the cssEntryFile) pulls in via @import never enter Metro's module graph. Editing one of them produces no graph delta, so the CSS entry is not re-transformed and nothing hot reloads until you also save global.css or any JS file. Same as #248, which was closed for lack of a repro.

Root cause

• compileTailwind.ts passes onDependency: () => void 0 to Tailwind's compile(). Tailwind reports every @import-resolved stylesheet there; the information is discarded.
• The Metro transformer only treats cssEntryFile as CSS, and the virtual module it emits declares no dependencies, so Metro never watches the imported files.

Repro (Expo SDK 57, RN 0.86, uniwind 1.12.0, iOS dev client)

1. global.css: @import "./src/components/ui/chip/tokens.css";
2. tokens.css: @theme static { --color-chip-primary: var(--color-blue-500); }
3. Render <View className="bg-chip-primary" />, then change the value in tokens.css only and save.

Nothing updates, also not after a JS reload. Saving global.css with a comment-only change applies it in ~80 ms. Adding a side-effect import "./tokens.css" to any JS module fixes it (Expo compiles non-web .css to an empty module), which shows Metro tracking is the only missing piece.

Proposed fix (native, ~20 lines)

1. compileTailwind: collect the .css paths outside node_modules that Tailwind reports through onDependency.
2. transform, native branch: prepend one require("<path relative to cssEntryFile>") per collected path to the virtual module. Expo turns those into empty modules, so the only effect is that Metro tracks the files and their edits produce a delta; the existing skipCache + traverseDependencies patch does the rest.

We run exactly this as a local bun patch on 1.12.0 and verified three token-only edits hot reload on device without any JS import. Open points: plain Metro (non-Expo) needs an empty-module shim for .css, and web is untouched. Happy to open a PR if this direction works for you.

[Brentlok]

Sounds good, feel free to open PR