feat(reader): integrate reader app into monorepo structure

- Restructure to apps/reader/apps/mobile/ pattern
- Rename package to @reader/mobile
- Add reader:dev and dev:reader:mobile scripts
- Update CLAUDE.md with monorepo commands
- Remove standalone .git repository
- Convert from npm to pnpm

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

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

apps/reader/.gitignore

@@ -0,0 +1,40 @@
+# Dependencies
+node_modules/
+
+# Build outputs
+dist/
+web-build/
+
+# Expo
+.expo/
+expo-env.d.ts
+
+# React Native (generated via expo prebuild)
+ios/
+android/
+
+# Environment
+.env
+.env.local
+.env.production
+
+# Debug
+npm-debug.*
+*.log
+
+# Certificates & Keys
+*.jks
+*.p8
+*.p12
+*.key
+*.mobileprovision
+*.orig.*
+
+# Metro
+.metro-health-check*
+
+# IDE
+.idea/
+
+# OS
+.DS_Store