fix: semantic-release authentication and token lifecycle management

Summary

Comprehensive fix for semantic-release authentication issues with multi-layer fallback mechanisms and token lifecycle management.

Changes

Authentication Fixes

• ✅ Added token validation pre-flight checks
• ✅ Implemented push permission testing with temporary tags
• ✅ Multi-layer auth cascade: PAT → CI_JOB_TOKEN → Manual
• ✅ Fixed YAML parser issues (backticks instead of command substitution)
• ✅ Added workflow rules for fix/ branches

Monitoring & Documentation

• ✅ Token expiration monitoring job (quarterly schedule)
• ✅ 30/60 day warning thresholds
• ✅ Comprehensive TOKEN_REQUIREMENTS.md documentation
• ✅ Manual fallback release mechanism

Key Improvements

• Non-blocking semantic-release with allow_failure
• Clear diagnostic messages for troubleshooting
• Production-ready with graceful degradation
• Security-focused with minimal required permissions

Fixes

• Resolves EGITNOPERMISSION errors
• Resolves EINVALIDGLTOKEN errors
• Handles protected branch restrictions
• Provides fallback for token rotation

Testing

• ✅ Local validation with gitlab-ci-local
• ✅ YAML syntax validated
• ✅ Pipeline #27829 successful