Add combined catalog export builder

.gitignore

@@ -1,6 +1,8 @@
 # Generated exports
 /exports/*
 !/exports/.gitkeep
+!/exports/catalog-latest.json
+!/exports/catalog-latest.json.gz
 
 # Generated indexes
 /indexes/*

exports/catalog-latest.json

@@ -0,0 +1,7 @@
+{
+    "format": "roundcount-catalog",
+    "catalog_version": 1,
+    "generated_at": "2026-07-15T16:19:54+00:00",
+    "product_count": 0,
+    "products": []
+}

tools/build-export.php

@@ -0,0 +1,132 @@
+<?php
+
+declare(strict_types=1);
+
+$root = dirname(__DIR__);
+$catalogDir = $root . '/catalog';
+$exportsDir = $root . '/exports';
+
+$products = [];
+$errors = [];
+
+if (!is_dir($catalogDir)) {
+    fwrite(STDERR, "Catalog directory not found: {$catalogDir}\n");
+    exit(1);
+}
+
+if (!is_dir($exportsDir) && !mkdir($exportsDir, 0775, true) && !is_dir($exportsDir)) {
+    fwrite(STDERR, "Unable to create exports directory: {$exportsDir}\n");
+    exit(1);
+}
+
+$iterator = new RecursiveIteratorIterator(
+    new RecursiveDirectoryIterator(
+        $catalogDir,
+        FilesystemIterator::SKIP_DOTS
+    )
+);
+
+foreach ($iterator as $file) {
+    if (!$file->isFile() || strtolower($file->getExtension()) !== 'json') {
+        continue;
+    }
+
+    $path = $file->getPathname();
+    $relativePath = substr($path, strlen($root) + 1);
+
+    $raw = file_get_contents($path);
+
+    if ($raw === false) {
+        $errors[] = "{$relativePath}: unable to read file";
+        continue;
+    }
+
+    try {
+        $record = json_decode($raw, true, 512, JSON_THROW_ON_ERROR);
+    } catch (JsonException $exception) {
+        $errors[] = "{$relativePath}: invalid JSON: {$exception->getMessage()}";
+        continue;
+    }
+
+    if (!is_array($record)) {
+        $errors[] = "{$relativePath}: root value must be an object";
+        continue;
+    }
+
+    $record['_catalog_path'] = $relativePath;
+    $products[] = $record;
+}
+
+if ($errors !== []) {
+    fwrite(STDERR, "Export build failed:\n\n");
+
+    foreach ($errors as $error) {
+        fwrite(STDERR, " - {$error}\n");
+    }
+
+    exit(1);
+}
+
+usort(
+    $products,
+    static function (array $left, array $right): int {
+        $leftManufacturer = strtolower((string) ($left['manufacturer'] ?? ''));
+        $rightManufacturer = strtolower((string) ($right['manufacturer'] ?? ''));
+
+        $manufacturerCompare = $leftManufacturer <=> $rightManufacturer;
+
+        if ($manufacturerCompare !== 0) {
+            return $manufacturerCompare;
+        }
+
+        $leftName = strtolower((string) ($left['product_name'] ?? ''));
+        $rightName = strtolower((string) ($right['product_name'] ?? ''));
+
+        return $leftName <=> $rightName;
+    }
+);
+
+$export = [
+    'format' => 'roundcount-catalog',
+    'catalog_version' => 1,
+    'generated_at' => gmdate('c'),
+    'product_count' => count($products),
+    'products' => $products,
+];
+
+try {
+    $json = json_encode(
+        $export,
+        JSON_PRETTY_PRINT |
+        JSON_UNESCAPED_SLASHES |
+        JSON_THROW_ON_ERROR
+    ) . PHP_EOL;
+} catch (JsonException $exception) {
+    fwrite(STDERR, "Unable to encode catalog export: {$exception->getMessage()}\n");
+    exit(1);
+}
+
+$jsonPath = $exportsDir . '/catalog-latest.json';
+$gzipPath = $exportsDir . '/catalog-latest.json.gz';
+
+if (file_put_contents($jsonPath, $json) === false) {
+    fwrite(STDERR, "Unable to write {$jsonPath}\n");
+    exit(1);
+}
+
+$compressed = gzencode($json, 9);
+
+if ($compressed === false) {
+    fwrite(STDERR, "Unable to compress catalog export\n");
+    exit(1);
+}
+
+if (file_put_contents($gzipPath, $compressed) === false) {
+    fwrite(STDERR, "Unable to write {$gzipPath}\n");
+    exit(1);
+}
+
+echo "Catalog export complete.\n";
+echo "Products exported: " . count($products) . "\n";
+echo "JSON: exports/catalog-latest.json\n";
+echo "Gzip: exports/catalog-latest.json.gz\n";