feat: add testing infrastructure — Vitest, Playwright, CI, git hooks

Add comprehensive testing covering 420 unit/handler tests across 24 Vitest
files, 9 Playwright E2E specs, accessibility scans, and visual regression.
Includes GitHub Actions CI, Husky pre-push hook, and TESTING.md docs.

e2e/member-profile.spec.js

@@ -0,0 +1,51 @@
+import { test, expect } from './helpers/fixtures.js'
+
+test.describe('Member profile page', () => {
+  test('profile page loads', async ({ adminPage }) => {
+    await adminPage.goto('/member/profile')
+    await expect(adminPage.getByText('Edit Profile')).toBeVisible()
+    await expect(adminPage.getByText('How you appear to other members')).toBeVisible()
+  })
+
+  test('form fields are present', async ({ adminPage }) => {
+    await adminPage.goto('/member/profile')
+
+    // Name input
+    await expect(adminPage.locator('input[placeholder="Your name"]')).toBeVisible()
+
+    // Bio textarea
+    await expect(adminPage.locator('textarea[placeholder*="Share your background"]')).toBeVisible()
+
+    // Save button
+    await expect(adminPage.getByRole('button', { name: 'Save Profile' })).toBeVisible()
+  })
+
+  test('bio field accepts input', async ({ adminPage }) => {
+    await adminPage.goto('/member/profile')
+
+    const bio = adminPage.locator('textarea[placeholder*="Share your background"]')
+    const saveBtn = adminPage.getByRole('button', { name: 'Save Profile' })
+
+    // Save button should start disabled (no changes yet)
+    await expect(saveBtn).toBeDisabled()
+
+    // Clear and type new text
+    await bio.clear()
+    await bio.fill('Game designer exploring cooperative structures')
+
+    // Save button should now be enabled
+    await expect(saveBtn).toBeEnabled()
+  })
+
+  test('pronouns field editable', async ({ adminPage }) => {
+    await adminPage.goto('/member/profile')
+
+    const pronouns = adminPage.locator('input[placeholder="e.g., she/her, they/them"]')
+    await expect(pronouns).toBeVisible()
+
+    await pronouns.clear()
+    await pronouns.fill('they/them')
+
+    await expect(pronouns).toHaveValue('they/them')
+  })
+})