Update boot-splash and explore headers theme (#13823)

<!-- CURSOR_SUMMARY -->
> [!NOTE]
> **Medium Risk**
> Primarily UI/UX changes across mobile and web; risk is moderate
because it removes a feature-flagged animated header/scroll behavior and
updates native splash assets, which could impact layout or launch
visuals if not tested on both platforms.
> 
> **Overview**
> Updates mobile bootsplash assets and theme colors on both Android and
iOS (new background/primary colors, new iOS logo asset set, and a
generated `assets/bootsplash/manifest.json`), and documents the
regeneration workflow in `packages/mobile/README.md`.
> 
> Refactors the mobile Explore/Search UI by removing the
collapsed/animated header and reanimated scroll handling/feature flag
wiring; the header becomes a simple static `TextInput` + filters bar
(with safer `scrollTo` calls) and `SearchExploreScreen` uses a plain
`IOScrollView` when showing Explore content.
> 
> On web, the desktop Explore hero background is switched from an
imported asset to a public URL (`landing-2026/landing.png`) to work
across Vite entry points, and the mobile Explore page now uses the
shared mobile header (`HeaderContext`/`hasDefaultHeader`) instead of
banner image preloading.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
579db55. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: dylanjeffers

package-lock.json

@@ -4,6 +4,20 @@ The Audius React Native mobile client
 
 ## Setup
 
+### Bootsplash (launch screen)
+
+The native splash screen uses [react-native-bootsplash](https://github.com/zoontek/react-native-bootsplash). To regenerate assets after changing the logo or background color (e.g. to match theme in `@audius/harmony`):
+
+```bash
+# Default [Neue] theme: light #F6F5F7, dark is set in values-night (Android) and Colors.xcassets (iOS)
+npx react-native-bootsplash generate src/assets/images/bootsplash_logo.png \
+  --background '#F6F5F7' \
+  --platforms ios,android \
+  --assets-output assets/bootsplash
+```
+
+This updates Android `res/values/colors.xml`, iOS `BootSplash.storyboard`, and `Colors.xcassets` / `Images.xcassets`. After regenerating, do a clean build and reinstall the app so the cached launch screen is replaced.
+
 ## Running iOS
 
 ```bash

packages/mobile/README.md

@@ -1,4 +1,5 @@
 <resources>
-    <color name="bootsplash_background">#353A51</color>
-    <color name="colorPrimary">#C74BD3</color>
+    <!-- Default [Neue] theme - dark -->
+    <color name="bootsplash_background">#000000</color>
+    <color name="colorPrimary">#806AD8</color>
 </resources>

packages/mobile/android/app/src/main/res/drawable-hdpi/bootsplash_logo.png

@@ -3,7 +3,7 @@
     <!-- Base application theme. -->
     <style name="AppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
         <!-- Customize your theme here. -->
-        <item name="android:textColor">#7E1BCC</item>
+        <item name="android:textColor">#7F6AD6</item>
 
         <!-- Set system bars background transparent -->
         <item name="android:statusBarColor">@android:color/transparent</item>

packages/mobile/android/app/src/main/res/drawable-mdpi/bootsplash_logo.png

@@ -1,4 +1,4 @@
 <resources>
-    <color name="bootsplash_background">#f7f7f8</color>
-    <color name="colorPrimary">#CC0FE0</color>
+    <color name="bootsplash_background">#f6f5f7</color>
+    <color name="colorPrimary">#7F6AD6</color>
 </resources>