Phase 1: Foundation - Database schema, core PHP structure, JWT auth, and User CRUD

Implemented:
- Database schema (SQLite) with tables: users, profiles, posts, swipes, matches, chats, chat_messages, events, notifications, relationships, post_likes, post_comments, refresh_tokens, media
- Core PHP structure following skeleton pattern (www/api/)
- JWT Authentication (register, login, refresh, logout)
- User profile CRUD (show, update, delete, search)
- User sub-resources (posts, friends, followers, following)
- Minimal Firebase JWT implementation for PHP without Composer

www/api/src/config/database.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * Database Configuration
+ */
+
+return [
+    'driver' => 'sqlite',
+    'database' => __DIR__ . '/../../database/sozial.db',
+    'options' => [
+        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+        PDO::ATTR_EMULATE_PREPARES => false,
+    ],
+];