feat(container-pull): add unified falcon-sensor with backward compatibility

[carlosmmatos]

🚀 Add Support for Unified Falcon Sensor Container Image

This PR introduces support for the new unified falcon-sensor image (version 7.31+) while maintaining full
backward compatibility through the new falcon-sensor-regional sensor type.

📋 Summary

• New Feature: Unified falcon-sensor image that works across all regions without region-specific paths
• Backward Compatibility: New falcon-sensor-regional type maintains traditional regional sensor
• Enhanced Version Matching: Smart version matching with improved error handling and user guidance
• Comprehensive Documentation: Updated with comparison, usage examples, and migration guidance

🎯 Motivation

Starting with Falcon sensor version 7.31, CrowdStrike introduced a simplified unified image sensor that:

• Removes region-specific repository paths
• Simplifies tag structure
• Provides a single image that works across all regions
• Reduces complexity for multi-region deployments

🔧 Technical Changes

New Sensor Type: falcon-sensor-regional

Traditional regional sensor (now explicit)

--type falcon-sensor-regional

Enhanced Registry Path Logic

• Unified: registry.crowdstrike.com/falcon-sensor/release/falcon-sensor
• Regional: registry.crowdstrike.com/falcon-sensor/[cloud-env]/release/falcon-sensor

Smart Version Matching

Exact version matching

--version 7.31.0

Partial version matching (gets latest 7.31.x)

--version 7.31

Major version matching (gets latest 7.x.x)

--version 7

Improved Error Handling

• Better version matching with helpful error messages
• Clear guidance on available versions and usage patterns
• Enhanced region validation logic

📖 Usage Examples

Unified (Recommended for 7.31+)

./falcon-container-sensor-pull.sh \
  --client-id <FALCON_CLIENT_ID> \
  --client-secret <FALCON_CLIENT_SECRET> \
  --type falcon-sensor \
  --copy myregistry.com/mynamespace

Regional (Backward Compatibility)

./falcon-container-sensor-pull.sh \
  --client-id <FALCON_CLIENT_ID> \
  --client-secret <FALCON_CLIENT_SECRET> \
  --type falcon-sensor-regional \
  --region us-2 \
  --copy myregistry.com/mynamespace

🔄 Migration Path

For Existing Users

• No action required: Existing falcon-sensor usage automatically gets the new unified image
• Regional sensor needed: Change -t falcon-sensor to -t falcon-sensor-regional

Deprecation Notice

• Users of falcon-sensor-regional will see a warning encouraging migration to the unified image
• Regional sensor will eventually be EOL (timeline TBD)