- Add tag name validation in Tag.get_or_create method
- Chinese names: max 16 characters
- Other languages: max 8 words
- Return error tags with uppercase English names when validation fails
- Ensure error tags are created through get_or_create to maintain database consistency
- Clean up database: removed 487,938 non-custom tags, keeping only 12 custom tags

Important performance optimization for handling large tag datasets:

- When total tags > 8192, limit 'pos' type tags to top 4096 by count
- Return all non-pos tags without limitation
- Significantly reduces memory usage and load time for large databases
- Maintains functionality while improving performance with massive tag counts