Enhancement: more configurable collection path

Current state

Currently, the path is always static except for the slug, specified by slugField.

The problem

Projects often require more custom paths, e.g.: locales, publish date

Proposal

Make the collection config an intersection like so (pseudocode):

type Collection = { /* base props */}
	& (
		{
			path: string // with * validation
			slugField: keyof fields	
		}
		| {
			path: (fields: Record<string, any>) => string // with * validation
			slugField: keyof fields // might not be required, we could manually specify the field by interpolation instead
		}
	)

Examples

Locales

export default defineConfig({
	// ...
	collections: {
		blog: collection({
			label: "Blog",
			path: ({ locale }) => `src/content/blog/${locale}/*`
			schema: {
				// ...
				locale: fields.text({ label: "Locale" }) // could be a relationship, whatever
			}
		})
	}
})

Publish date

export default defineConfig({
	// ...
	collections: {
		blog: collection({
			label: "Blog",
			path: ({ publishDate }) => `src/content/blog/${publishDate}.*`
			schema: {
				// ...
				publishDate: fields.date({ label: "Published date" })
			}
		})
	}
})

Start by tracing the TypeScript definitions and implementation behind defineConfig and collection, focusing on the current static path and slugField behavior. Review how schema fields are exposed to path configuration and how wildcard validation works; done means supporting the proposed field-based path forms with clear typing and validation.