Add GitLab CI/CD pipeline with Fastlane automation

Overview

Implements comprehensive CI/CD pipeline for iOS with GitLab CI and Fastlane automation.## Changes- GitLab CI pipeline with build, test, quality, deploy stages- Fastlane configuration for TestFlight deployment- Automated testing with code coverage- Security scanning (npm audit, Snyk)- Build caching for faster pipelines## Epic Hierarchy- Part of mobile-section&4 (Mobile DevOps & Infrastructure)- Supports mobile-section&2 (iOS React Native Migration)- Parent: mobile-section&1 (Q1 2025: Mobile Platform Modernization)- Grandparent: acme-corp&4 (Q1 2025: AI-Powered Mobile Platform Initiative)## Benefits- Automated quality gates- Faster feedback loops- Consistent releases- Security scanning on every MRCloses #8 (closed)