chore(sync): updated a script to properly handle module packages

[lukidzi]

Summary

Fixes the upstream synchronization automation to support multi-module tagging and resolves GitHub Actions output format errors.

Changes

1. Refactored version detection script (.github/scripts/get-version-tags.sh)

Problem: The original script only tracked the root module tag and failed in GitHub Actions with JSON format errors.

Solution: Complete rewrite with the following improvements:

• Multi-module support: Now detects and tracks tags across all 5 modules (root, envoy, contrib, ratelimit, xdsmatcher)
• Added reusable functions: strip_kong_suffix(), process_module_tags()
• Used loops and arrays instead of duplicating logic for each module
• Centralized module list in MODULES array for easy maintenance
  Actions can parse
• Enhanced detection logic:
  • Identifies all new upstream tags per module since last Kong release
  • Determines if rebase is needed (root version changed)
  • Outputs multiple tags as JSON array for workflow consumption
• Better error handling: Added set -e and proper exit codes

2. Updated sync workflow (.github/workflows/sync-with-upstream.yaml)

• Decoupled detection from sync: Tag detection now runs independently, not only when new commits exist
• Multi-tag support: Workflow now creates all module tags (not just root)
• New outputs consumed:
  • needs_release: Boolean indicating if action is needed
  • needs_rebase: Boolean indicating if rebase is required
  • new_tags: JSON array of all tags to create
• Improved rebase logic: Uses --onto with proper base commit detection
• Better workflow control: Added separate steps for "no action needed" vs "release with rebase"

3. Enhanced documentation (DEVELOPMENT.md)

• Added multi-module tagging section: Explains upstream's new multi-module tag structure
• Improved conflict resolution instructions:
  • Better explanation of branch structure
  • Step-by-step rebase instructions with examples
  • Clarified that Kong tags point to HEAD (custom commits on top)
• Manual release examples: Shows how to create all module tags when doing custom releases