fix(react-ui): re-export full ThemeProvider barrel from main entry

[ankit-thesys]

Summary

packages/react-ui/src/index.ts was hand-listing only a subset of ./components/ThemeProvider's exports — useTheme and ThemeContext were left off. Combined with the "./*" exports map (which compiles each component to a standalone subpath chunk while the main entry inlines its own copy), this produced two separate createContext() calls at runtime:

• <ThemeProvider> imported from @openuidev/react-ui writes to the main bundle's ThemeContext.
• useTheme imported from @openuidev/react-ui/ThemeProvider reads from the subpath chunk's ThemeContext.

Two contexts, never the same instance. useTheme() always returned the default value when <ThemeProvider> was mounted from the main entry — the only place useTheme was reachable from.

Downstream impact

Caused a real regression in @thesys/artifact: PresentationThemeProvider reads ambient mode via useTheme() so it can scope a second <ThemeProvider cssSelector=".thesys-slide"> for slide-scale typography. Because of the dual-context bug, slides rendered in light mode regardless of the outer <ThemeProvider mode="dark">. Workaround was passing an explicit mode prop into every PresentationThemeProvider instance.

Fix

Replace the hand-listed re-export block with export * from "./components/ThemeProvider" — the pattern used by every other component in this barrel. Picks up useTheme + ThemeContext (which were missing) alongside ThemeProps and ThemeMode (which were previously re-exported via separate lines that are now redundant and removed).

Once consumers migrate from @openuidev/react-ui/ThemeProvider to @openuidev/react-ui for these symbols, both paths share the same compiled chunk = same ThemeContext instance.

-export {
-  ThemeProvider,
-  createTheme,
-  defaultDarkTheme,
-  defaultLightTheme,
-  swatchTokens,
-  type Theme,
-} from "./components/ThemeProvider";
-export type { ThemeProps } from "./components/ThemeProvider/ThemeProvider";
-export type { ThemeMode } from "./components/ThemeProvider/types";
+export * from "./components/ThemeProvider";

Test plan

• pnpm --filter @openuidev/react-ui typecheck (passes locally — no ambiguous-export errors)
• pnpm --filter @openuidev/react-ui build (passes locally; built tarball verified to expose useTheme and ThemeContext on the main dist/index.d.mts)
• Verified end-to-end against @thesys/artifact consumer: with the rebuilt react-ui overridden into the consumer and all useTheme imports flipped to the main entry, slides correctly inherit the outer <ThemeProvider mode> setting.

Notes

• No public API removals. useTheme, ThemeContext, ThemeProps, ThemeMode, Theme, ThemeProvider, createTheme, default themes, and swatchTokens remain exported from the main entry. The wildcard also surfaces previously-only-via-subpath helpers (black, white, withAlpha, swatch, swatchToken, granular theme interfaces) — these were already public via the subpath; this just promotes them to the main entry.
• Subpath import (@openuidev/react-ui/ThemeProvider) still works for any existing consumer that depends on it. Consumers mixing subpath useTheme with main-entry <ThemeProvider> will need to migrate to the main entry to get the dedup benefit.

[i-subham23]

L.G.