feat(ui): native vessel, HTML vessel update, native hello examples, profile card, UI tools

el-native vessel: El-level wrappers around __widget_* C builtins, exposing
vstack, label, button, text_field, etc. as clean El functions for application code.

el-html/main.elh: updated extern declarations for the HTML vessel's codegen API.

native-hello: cross-platform desktop example (AppKit/GTK4/Win32/SDL2) with
build scripts, Dockerfiles for Linux/Pi, and Win32 cross-compile support.

native-hello-android: Gradle project with ElBridge integration and build script.

native-hello-ios: Xcode project for the iOS UIKit target.

profile-card: manifest.el for a styling/layout/i18n example app that exercises
el-style, el-layout, el-i18n, el-config, and el-secrets vessels.

ui/tools/native-codegen: Python codegen pass (el_ui_native_codegen.py) that
lowers el-ui component DSL to el-native vessel calls, plus build script and
test fixtures.

ui/examples/native-hello-android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <application
+        android:name=".ElApp"
+        android:label="el-native"
+        android:theme="@style/Theme.AppCompat.Light.NoActionBar"
+        android:allowBackup="false"
+        android:supportsRtl="true">
+
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:configChanges="orientation|screenSize|keyboardHidden">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+    </application>
+
+</manifest>