feat: ship Peptide Reconstitution Calculator v1.0.0

Interactive reconstitution calculator with peptide-specific presets.

Core features:
- [prc_calculator] shortcode with instant client-side math
- Concentration (mg/mL), mcg/unit, injection volume, syringe units, doses/vial
- Live presets from PR Core dosing data (graceful fallback to 8 defaults)
- REST API (prc/v1): presets list/detail + server-side calculate
- Transient-cached presets with event-driven invalidation
- Dark mode + responsive design (320px+)
- Full teardown in uninstall.php

12 PHP files (max 241 lines), 1 JS file, 1 CSS file.
CI: PHP lint 8.1-8.3, PHPCS WordPress, 300-line check.

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

includes/class-prc-calculator.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * Main orchestrator for the Reconstitution Calculator plugin.
+ *
+ * What: Boots all subsystems — shortcode, REST API, admin settings.
+ * Who calls it: plugins_loaded hook in bootstrap.
+ * Dependencies: PRC_Shortcode, PRC_Rest_Controller, PRC_Preset_Provider.
+ *
+ * @see class-prc-shortcode.php    — Frontend calculator widget.
+ * @see class-prc-rest-controller.php — REST endpoints for presets.
+ * @see class-prc-preset-provider.php — PR Core integration + fallback defaults.
+ */
+
+declare(strict_types=1);
+
+/**
+ * Central boot class — wires hooks for the entire plugin.
+ */
+class PRC_Calculator {
+
+	/**
+	 * Boot the plugin — called on plugins_loaded.
+	 *
+	 * Registers the shortcode, REST routes, and admin notice
+	 * if PR Core is not active.
+	 *
+	 * @return void
+	 */
+	public static function boot(): void {
+		// Frontend shortcode — always available.
+		$shortcode = new PRC_Shortcode();
+		add_action( 'init', [ $shortcode, 'register' ] );
+
+		// REST API — serves presets to the JS calculator.
+		add_action( 'rest_api_init', [ new PRC_Rest_Controller(), 'register_routes' ] );
+
+		// Cache invalidation — keep presets in sync with PR Core dosing data.
+		PRC_Cache_Listener::register();
+
+		// Admin notice when PR Core is absent.
+		if ( is_admin() && ! self::is_pr_core_active() ) {
+			add_action( 'admin_notices', [ __CLASS__, 'render_pr_core_notice' ] );
+		}
+	}
+
+	/**
+	 * Check whether Peptide Repo Core is active.
+	 *
+	 * Looks for the PR_CORE_VERSION constant which is defined
+	 * in peptide-repo-core.php's bootstrap.
+	 *
+	 * @return bool True if PR Core is loaded.
+	 */
+	public static function is_pr_core_active(): bool {
+		return defined( 'PR_CORE_VERSION' );
+	}
+
+	/**
+	 * Render an admin notice suggesting PR Core installation.
+	 *
+	 * Not a blocker — the calculator works standalone with built-in
+	 * defaults. PR Core just unlocks peptide-specific presets.
+	 *
+	 * @return void Side effect: outputs HTML notice.
+	 */
+	public static function render_pr_core_notice(): void {
+		$screen = get_current_screen();
+		if ( null === $screen ) {
+			return;
+		}
+
+		// Only show on plugins page and the calculator's own pages.
+		$show_on = [ 'plugins', 'settings_page_prc-settings' ];
+		if ( ! in_array( $screen->id, $show_on, true ) ) {
+			return;
+		}
+
+		printf(
+			'<div class="notice notice-info is-dismissible"><p>%s</p></div>',
+			esc_html__(
+				'Peptide Reconstitution Calculator: Install Peptide Repo Core to unlock peptide-specific presets with real dosing data. The calculator works without it using built-in defaults.',
+				'peptide-reconstitution-calculator'
+			)
+		);
+	}
+}