Initial import of fitme3070.pt platform

Plain-PHP fleet platform with id.andmore.pt SSO. Wires shared/platform-tools
as a submodule (platform_update, backups, git/migration tools) like the other
platforms.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

config/functions_settings.php

@@ -0,0 +1,91 @@
+<?php
+// ─── DB-backed system settings with file-based cache ─────────────────────────
+//
+// Settings live in the `system_settings` table (key→value). To avoid a query
+// on every page load, the full set is cached as a PHP array literal under
+// config/cache/settings.cache.php — read via require, served from opcache
+// in memory. The cache is invalidated (file deleted) on every db_update_setting().
+//
+// Public API:
+//   setting($key, $default = null) — cached read
+//   settings_all()                  — cached array
+//   db_get_all_settings($pdo)       — bypasses cache
+//   db_update_setting($pdo, $key, $value, $userId = null) — UPSERT + invalidate
+//
+// $pdo is read from the global scope only by db_*() helpers; setting() and
+// settings_all() never touch the DB once the cache exists.
+
+function _settings_cache_path(): string {
+    return __DIR__ . '/cache/settings.cache.php';
+}
+
+function settings_cache_clear(): void {
+    $path = _settings_cache_path();
+    if (is_file($path)) {
+        @unlink($path);
+    }
+}
+
+function settings_cache_write(array $data): void {
+    $path = _settings_cache_path();
+    $dir  = dirname($path);
+    if (!is_dir($dir)) {
+        @mkdir($dir, 0775, true);
+    }
+    $tmp  = $path . '.' . bin2hex(random_bytes(4)) . '.tmp';
+    $code = "<?php\nreturn " . var_export($data, true) . ";\n";
+    if (@file_put_contents($tmp, $code, LOCK_EX) === false) {
+        return;
+    }
+    @rename($tmp, $path);
+    if (function_exists('opcache_invalidate')) {
+        @opcache_invalidate($path, true);
+    }
+}
+
+function db_get_all_settings(PDO $pdo): array {
+    $rows = $pdo->query("SELECT setting_key, setting_value FROM system_settings")
+                ->fetchAll(PDO::FETCH_KEY_PAIR);
+    return $rows ?: [];
+}
+
+function settings_cache_load(): array {
+    static $loaded = null;
+    if ($loaded !== null) {
+        return $loaded;
+    }
+    $path = _settings_cache_path();
+    if (is_file($path)) {
+        $data = @include $path;
+        if (is_array($data)) {
+            return $loaded = $data;
+        }
+    }
+    global $pdo;
+    if (!($pdo instanceof PDO)) {
+        return $loaded = [];
+    }
+    $data = db_get_all_settings($pdo);
+    settings_cache_write($data);
+    return $loaded = $data;
+}
+
+function settings_all(): array {
+    return settings_cache_load();
+}
+
+function setting(string $key, $default = null) {
+    $data = settings_cache_load();
+    return array_key_exists($key, $data) ? $data[$key] : $default;
+}
+
+function db_update_setting(PDO $pdo, string $key, string $value, ?int $userId = null): void {
+    $s = $pdo->prepare(
+        "INSERT INTO system_settings (setting_key, setting_value, updated_by)
+         VALUES (?, ?, ?)
+         ON DUPLICATE KEY UPDATE setting_value = VALUES(setting_value),
+                                 updated_by    = VALUES(updated_by)"
+    );
+    $s->execute([$key, $value, $userId]);
+    settings_cache_clear();
+}