config: remove unused database and logging configuration options (#349)

## Motivation and Context

Cleanup unused configuration, to avoid confusing ourselves in future

## How Has This Been Tested?

Everything still runs happily locally, also searched for references

## Breaking Changes

None

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

internal/config/config.go

@@ -17,9 +17,6 @@ type Config struct {
 	ServerAddress       string       `env:"SERVER_ADDRESS" envDefault:":8080"`
 	DatabaseType        DatabaseType `env:"DATABASE_TYPE" envDefault:"postgresql"`
 	DatabaseURL         string       `env:"DATABASE_URL" envDefault:"postgres://localhost:5432/mcp-registry?sslmode=disable"`
-	DatabaseName        string       `env:"DATABASE_NAME" envDefault:"mcp-registry"`
-	CollectionName      string       `env:"COLLECTION_NAME" envDefault:"servers_v2"`
-	LogLevel            string       `env:"LOG_LEVEL" envDefault:"info"`
 	SeedFrom            string       `env:"SEED_FROM" envDefault:""`
 	Version             string       `env:"VERSION" envDefault:"dev"`
 	GithubClientID      string       `env:"GITHUB_CLIENT_ID" envDefault:""`