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/withChangeNativeAndroidTextToWhite.ts

@@ -0,0 +1,33 @@
+import { readFileSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { type ConfigPlugin, withDangerousMod } from "expo/config-plugins";
+
+const withChangeNativeAndroidTextToWhite: ConfigPlugin = (expoConfig) =>
+  withDangerousMod(expoConfig, [
+    "android",
+    (modConfig) => {
+      if (modConfig.modRequest.platform === "android") {
+        const stylesXmlPath = join(
+          modConfig.modRequest.platformProjectRoot,
+          "app",
+          "src",
+          "main",
+          "res",
+          "values",
+          "styles.xml",
+        );
+
+        let stylesXml = readFileSync(stylesXmlPath, "utf8");
+
+        stylesXml = stylesXml.replace(
+          /@android:color\/black/g,
+          "@android:color/white",
+        );
+
+        writeFileSync(stylesXmlPath, stylesXml, { encoding: "utf8" });
+      }
+      return modConfig;
+    },
+  ]);
+
+export default withChangeNativeAndroidTextToWhite;