refactor: migrate app.config and Expo config plugins to TypeScript

Migrate the dynamic Expo config and all 12 local config plugins from
CommonJS .js to typed TypeScript:

- app.config.js -> app.config.ts (typed ConfigContext/ExpoConfig,
  behavior-identical port)
- plugins/*.js -> plugins/*.ts with `ConfigPlugin` typings from
  expo/config-plugins; plugin options are now type-checked (withGitPod)
- app.json plugin references updated to the .ts paths
- imports unified on expo/config-plugins (some plugins used the
  @expo/config-plugins alias)

Node evaluates the config at prebuild time and cannot parse TypeScript
plugin modules on its own (verified empirically: Expo transpiles
app.config.ts itself but not its imports), so the documented tsx
approach is used: `import "tsx/cjs"` at the top of app.config.ts plus
tsx as a devDependency.

Validation: resolved prebuild configs (expo config --type prebuild) are
byte-identical to the old JS config for both mobile and TV (modulo
plugin path extensions and the builtAt timestamp); full
`bun run prebuild` and `bun run prebuild:tv` pass and all Android
plugin mods are present in the generated project (media3 exclusions,
gradle properties, cast activity, network security config, alert
colors).

plugins/withGradleProperties.ts

@@ -0,0 +1,48 @@
+import type { ExpoConfig } from "expo/config";
+import {
+  AndroidConfig,
+  type ConfigPlugin,
+  withGradleProperties,
+} from "expo/config-plugins";
+
+function setGradlePropertiesValue(
+  config: ExpoConfig,
+  key: string,
+  value: string,
+): ExpoConfig {
+  return withGradleProperties(config, (exportedConfig) => {
+    const props = exportedConfig.modResults;
+    const keyIdx = props.findIndex(
+      (item) => item.type === "property" && item.key === key,
+    );
+    const property: AndroidConfig.Properties.PropertiesItem = {
+      type: "property",
+      key,
+      value,
+    };
+
+    if (keyIdx >= 0) {
+      props.splice(keyIdx, 1, property);
+    } else {
+      props.push(property);
+    }
+
+    return exportedConfig;
+  });
+}
+
+const withCustomGradleProperties: ConfigPlugin = (config) => {
+  // Expo 52 is not setting this
+  // https://github.com/expo/expo/issues/32558
+  config = setGradlePropertiesValue(config, "android.enableJetifier", "true");
+
+  // Increase memory
+  config = setGradlePropertiesValue(
+    config,
+    "org.gradle.jvmargs",
+    "-Xmx4096m -XX:MaxMetaspaceSize=1024m",
+  );
+  return config;
+};
+
+export default withCustomGradleProperties;