Fixed two critical issues in the sync-upstream.yml workflow:
1. Wildcard conflict resolution: The previous logic used wildcards (profiles/*.yml)
that overlapped with custom files (profiles/*Micro*.yml), causing custom files
to be overwritten. Now uses a two-phase explicit merge strategy:
- Phase 1: Accept all upstream changes
- Phase 2: Explicitly restore custom files by exact path
2. Wrong push target: Changed from 'main || master' to 'stable' branch
This ensures weekly syncs will now work correctly while preserving:
- profiles/1080p Micro.yml, 720p Micro.yml
- custom_formats/Micro Encode Tier 1/2/3.yml
- regex_patterns/BONE.yml, ETHEL.yml, GalaxyRG.yml, TGx.yml
- custom_formats/Foreign Release Groups.yml