fix(react): export dist CSS entrypoints for Metro compatibility (#6962)

* fix(react): export dist CSS entrypoints for Metro compatibility

Metro warns when resolving Amplify UI CSS from React Native web/DOM usage because it probes the built subpath `./dist/styles.css`, which was not listed in package `exports`. Add explicit `./dist/styles.css` export aliases for `@aws-amplify/ui-react` and `@aws-amplify/ui-react-liveness` so Metro no longer have to implicitly fallback to file-based resolution.

```
WARN  Attempted to import the module "…/node_modules/styles.css" which is not listed
in the "exports" of "…/@aws-amplify/ui-react" under the requested subpath
"./dist/styles.css". Falling back to file-based resolution. Consider updating the
call site or asking the package maintainer(s) to expose this API.

WARN  Attempted to import the module "…/node_modules/styles.css" which is not listed
in the "exports" of "…/@aws-amplify/ui-react-liveness" under the requested subpath
"./dist/styles.css". Falling back to file-based resolution. …
```

* chore: add changeset

---------

Co-authored-by: Philipp Andreas Paul <phandpau@amazon.de>

Author: ashuvssut

.changeset/warm-dogs-return.md

@@ -0,0 +1,6 @@
+---
+'@aws-amplify/ui-react-liveness': patch
+'@aws-amplify/ui-react': patch
+---
+
+Fix Metro warnings by explicitly exporting dist CSS entrypoints in package.json. Added `./dist/styles.css` export aliases to prevent Metro from implicitly falling back to file-based resolution.

packages/react-liveness/package.json

@@ -9,10 +9,12 @@
       "import": "./dist/esm/index.mjs",
       "require": "./dist/index.js"
     },
-    "./styles.css": "./dist/styles.css"
+    "./styles.css": "./dist/styles.css",
+    "./dist/styles.css": "./dist/styles.css"
   },
   "browser": {
-    "./styles.css": "./dist/styles.css"
+    "./styles.css": "./dist/styles.css",
+    "./dist/styles.css": "./dist/styles.css"
   },
   "types": "dist/types/index.d.ts",
   "sideEffects": [
@@ -87,4 +89,4 @@
       "limit": "229 kB"
     }
   ]
-}
+}

packages/react/package.json

@@ -20,12 +20,14 @@
       "require": "./dist/server.js"
     },
     "./styles.css": "./dist/styles.css",
+    "./dist/styles.css": "./dist/styles.css",
     "./styles.layer.css": "./dist/styles.layer.css",
     "./styles/*": "./dist/styles/*",
     "./primitives.json": "./dist/primitives.json"
   },
   "browser": {
-    "./styles.css": "./dist/styles.css"
+    "./styles.css": "./dist/styles.css",
+    "./dist/styles.css": "./dist/styles.css"
   },
   "types": "dist/types/index.d.ts",
   "license": "Apache-2.0",