Add Playwright accessibility and mobile layout e2e tests

Set up end-to-end test infrastructure with Docker Compose test
environment, Playwright config, and automated global setup/teardown
that seeds a test database and creates fixtures via the API.

Tests cover 11 pages across both dark/light themes for WCAG 2.0 AA
accessibility (axe-core), and across 3 viewports (mobile, tablet,
desktop) for horizontal overflow and touch target validation.

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

.beans/nuzlocke-tracker-dpw7--modernize-website-design-and-look-and-feel.md

@@ -1,11 +1,11 @@
 ---
 # nuzlocke-tracker-dpw7
 title: Modernize website design and look-and-feel
-status: in-progress
+status: completed
 type: feature
 priority: normal
 created_at: 2026-02-17T19:16:39Z
-updated_at: 2026-02-17T21:04:45Z
+updated_at: 2026-02-20T19:05:21Z
 ---
 
 Overhaul the UI to a dark-first, techy aesthetic with a cohesive brand identity derived from the ANT steel ant logo.
@@ -93,9 +93,9 @@ Self-host **Geist** (or Inter/JetBrains Mono pairing):
 - [x] Update badge/indicator styles (TypeBadge, RuleBadges, EncounterMethodBadge)
 - [x] Add dark/light mode toggle to nav
 - [x] Polish hover states and transitions across all interactive elements
-- [ ] Add automated Playwright accessibility and mobile layout tests
-- [ ] Verify accessibility (contrast ratios, focus indicators)
-- [ ] Verify mobile layout and touch targets
+- [x] Add automated Playwright accessibility and mobile layout tests
+- [x] Verify accessibility (contrast ratios, focus indicators)
+- [x] Verify mobile layout and touch targets
 
 ## Automated verification approach