feat: implement build-time @store PostCSS directive

plugins/postcss-storestyles/index.js

@@ -0,0 +1,34 @@
+/**
+ * @type {import('postcss').PluginCreator}
+ */
+module.exports = (opts = {}) => {
+	return {
+		postcssPlugin: 'postcss-storestyles',
+		/*
+		 * Resolve `@store` blocks in `Once`, before Tailwind's own `Once`
+		 * compiler pass runs. PostCSS fires every plugin's `Once` handler
+		 * (in registration order) ahead of the node-visitor traversal, so
+		 * a plain `AtRule` visitor would run too late — Tailwind/lightningcss
+		 * would already have seen `@store` and flagged it as an unknown
+		 * at-rule. Registering this plugin before `@tailwindcss/postcss`
+		 * therefore guarantees `@store` is gone before Tailwind compiles.
+		 */
+		Once: (root) => {
+			const storeCode = opts.storeCode || process.env.NEXT_PUBLIC_STORE_CODE;
+			const shopSystem = String(storeCode).split('_').shift();
+			root.walkAtRules('store', (atRule) => {
+				if (
+					atRule.params != shopSystem &&
+					!atRule.params.startsWith(`${shopSystem}_`) &&
+					atRule.params !== storeCode
+				) {
+					atRule.remove();
+				} else {
+					atRule.replaceWith(atRule.nodes);
+				}
+			});
+		},
+	};
+};
+
+module.exports.postcss = true;