Root cause: Projects with duplicate (code, variant) pairs fail to sync
due to unique constraint on server. Example: multiple "OPS-1934" projects
with variant="Dell" where one already exists on server.
Fixes:
1. Sync service now detects duplicate (code, variant) on server and links
local project to existing server project instead of failing
2. Local repair checks for duplicate (code, variant) pairs and deduplicates
by appending UUID suffix to variant
3. Modal now scrollable with fixed header/footer (max-h-90vh)
This allows users to sync projects that were created offline with
conflicting codes/variants without losing data.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>