feat: implement responsive ReadingView with preference support

Implements Task 3 from Bible Reader 2025 plan:
- Created lib/reading-preferences.ts with 4 presets (default, dyslexia, highContrast, minimal)
- Implemented loadPreferences/savePreferences using localStorage
- Added getCSSVariables for dynamic styling
- Created ReadingView component with full mobile responsiveness
- Touch interaction: tap top third shows header, bottom third toggles controls
- Verse text is clickable with hover effects
- Navigation controls (prev/next chapter, settings button)
- Created test file for preferences

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

__tests__/lib/reading-preferences.test.ts

@@ -0,0 +1,16 @@
+import { getCSSVariables, getPreset } from '@/lib/reading-preferences'
+
+describe('reading-preferences', () => {
+  it('returns default preset', () => {
+    const preset = getPreset('default')
+    expect(preset.fontFamily).toBe('georgia')
+    expect(preset.fontSize).toBe(18)
+  })
+
+  it('generates CSS variables correctly', () => {
+    const preset = getPreset('dyslexia')
+    const vars = getCSSVariables(preset)
+    expect(vars['--font-size']).toBe('18px')
+    expect(vars['--letter-spacing']).toBe('0.08em')
+  })
+})