feat: initial Playwright smoke suite

20 tests across 5 files covering all plugin surfaces on staging:
- Homepage load and PHP fatal detection
- Reconstitution Calculator shortcode + math
- Peptide Search AI widget + AJAX response
- Admin: all plugins active, PSA + PRAutoBlogger settings pages
- REST API: prc/v1/presets, peptides/v1/search, compounds, CPT types

Staging shortcode pages:
  /reconstitution-calculator/ - [prc_calculator]
  /search-peptides/           - [peptide_search]
  /peptide-directory/         - [peptide_directory]

GHA workflow: smoke.yml supports manual dispatch + workflow_call
for use as a deploy gate from plugin repos.

tests/01-reconstitution-calculator.spec.ts

@@ -0,0 +1,69 @@
+/**
+ * 01-reconstitution-calculator.spec.ts
+ *
+ * What: Smoke-tests the Peptide Reconstitution Calculator (PRC) plugin.
+ *       Verifies the shortcode renders, presets load, and basic math produces
+ *       a non-zero result — catching broken PHP, failed asset enqueue, or
+ *       missing PR Core integration.
+ * Who triggers it: Playwright chromium project (post-auth setup).
+ * Dependencies: peptide-reconstitution-calculator plugin active, [prc_calculator]
+ *               shortcode on the page at CALC_PAGE_PATH.
+ *
+ * @see C:\Users\ongte\apps\Peptide Repo CTO\app-maps\peptide-reconstitution-calculator.md
+ */
+
+import { test, expect } from '@playwright/test';
+
+const CALC_PATH = process.env.CALC_PAGE_PATH ?? '/reconstitution-calculator/';
+
+test.describe('Reconstitution Calculator', () => {
+  test.beforeEach(async ({ page }) => {
+    const res = await page.goto(CALC_PATH);
+    // Tolerate 200 or 301 (redirect to trailing slash)
+    expect([200, 301]).toContain(res?.status());
+    await page.waitForLoadState('networkidle');
+  });
+
+  test('shortcode widget renders on page', async ({ page }) => {
+    // The shortcode wraps the widget in a container with class prc-calculator
+    // or similar; at minimum a <select> for peptide presets must exist.
+    const widget = page.locator('.prc-calculator, [data-prc], #prc-calculator').first();
+    await expect(widget).toBeVisible({ timeout: 10_000 });
+  });
+
+  test('peptide preset dropdown is populated', async ({ page }) => {
+    // At minimum the 8 hardcoded defaults; more if PR Core is active
+    const select = page.locator('select').first();
+    await expect(select).toBeVisible();
+    const options = await select.locator('option').count();
+    expect(options).toBeGreaterThan(1); // >1 means at least one peptide beyond placeholder
+  });
+
+  test('fills inputs and gets a numeric result', async ({ page }) => {
+    // Select BPC-157 or the first non-placeholder option
+    const select = page.locator('select').first();
+    const firstPeptide = select.locator('option').nth(1);
+    const firstValue = await firstPeptide.getAttribute('value');
+    await select.selectOption(firstValue ?? '');
+
+    // Fill reconstitution volume (mL) — use a known valid value
+    const volInput = page.locator('input[name*="recon"], input[placeholder*="mL"], input[type="number"]').first();
+    await volInput.fill('2');
+
+    // Fill desired dose
+    const doseInput = page.locator('input[name*="dose"], input[placeholder*="dose"], input[type="number"]').nth(1);
+    await doseInput.fill('250');
+
+    // Trigger calculation (button or auto-calculate on input)
+    const calcButton = page.locator('button[type="submit"], button:has-text("Calculate")');
+    if (await calcButton.count() > 0) {
+      await calcButton.first().click();
+    }
+
+    // Results container should show a non-zero concentration or injection volume
+    const results = page.locator('.prc-results, .calculator-results, [data-prc-result]').first();
+    await expect(results).toBeVisible({ timeout: 5_000 });
+    const resultText = await results.textContent();
+    expect(resultText).toMatch(/\d+(\.\d+)?/); // contains at least one number
+  });
+});