Initial commit: Flutter app + PHP/MySQL backend on Hostinger

Replaces Firebase with a self-hosted PHP/MySQL API served from
winded.prymsolutions.com. Includes full backend (schema, auth, events,
teams, brackets, suggestions, stats, media, file upload) and updated
Flutter repositories and domain models.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

android/app/src/main/res/drawable-v21/launch_background.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>