fix: database unique constraints (#2594)

* fixed missing migration name

* added unique constraints to all m2m tables

* fixed bug trying to create duplicate tags

* added more unique constraints

* fixed duplicate seeder data

* updated tests

* fixed seed rollback error

mealie/services/scraper/scraped_extras.py

@@ -33,8 +33,13 @@ class ScrapedExtras:
         repo = ctx.repos.tags.by_group(ctx.group_id)
 
         tags = []
+        seen_tag_slugs: set[str] = set()
         for tag in self._tags:
             slugify_tag = slugify(tag)
+            if slugify_tag in seen_tag_slugs:
+                continue
+
+            seen_tag_slugs.add(slugify_tag)
 
             # Check if tag exists
             if db_tag := repo.get_one(slugify_tag, "slug"):