fix(styles): stop scanning every component for utility sources

Component discovery is not utility-source discovery: scanning all
built-in and plugin component directories made Tailwind/Iconify generate
rules for components the app never renders. Packages that need scanning
opt in through styles.source.

Pre-existing working-tree change, committed as-is rather than authored
here.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/dev-server/src/index.ts

@@ -440,10 +440,9 @@ export async function startServer(opts: ServeOptions): Promise<RunningServer> {
       config: opts.stylesConfig,
       appRoot,
       publicDir: join(appRoot, "public"),
-      sources: [
-        ...componentDirs,
-        ...pluginContributions.styles.flatMap((style) => (style.source ? [style.source] : [])),
-      ],
+      // Component discovery is separate from utility-source discovery.
+      // Packages that need Tailwind scanning opt in via styles.source.
+      sources: pluginContributions.styles.flatMap((style) => (style.source ? [style.source] : [])),
       entries: pluginContributions.styles.flatMap((style) => (style.entry ? [style.entry] : [])),
     },
     theme,