Various fixes

[NicoPennec]

Problem

• The custom metadata Tag List may fail due to invalid imported values...
• Knowing the number of productions in Kitsu would be helpful.
• Some npm dependencies are outdated.
• Some legacy routes still exist.

Solution

• Handle metadata type changes in ComboboxTag by accepting non-string modelValue (e.g., Number) and filtering out values not present in the available options.
• Add counters to the production list.
• Bump npm dependencies: migrate to Vite 8.x.
• Remove unused routes.