[ia0]

CC @corkamig

The flow is:

• Identify with custom rules (and exit if there's a match): the rationale is that it's for hot-fixes
• Identify with resolvers (and exit if there's a match)
• Identify with builtin rules (and exit if there's a match): those will eventually disappear once resolvers cover them
• Identify with model (but rules and resolvers may veto)

There is still one thing to be done, but it can be done later since it needs KB synchronization: the same way we have a column for "supported by the model" and "supported by the rules" for each content type, we also want a column for the resolvers. I think the simplest way to do it is to have a rust/gen/resolvers/content_types the same way we have rust/gen/rules/content_types except it would be manually edited instead of autogenerated.