[ifmelate]

prune_types: true declares in types.dart only the enums, input types, custom scalars and possibleTypes entries that the operations and fragments of document_paths use.

• Collected from all documents: enums and scalars of selected fields (fragments included), variable types with every input/enum/scalar their fields reach, interfaces and unions that are selected or used as a type condition.
• Off by default: code using a type no operation selects would stop compiling. Operation result types only; warns with result_types: schema or types_import.
• GitLab's public schema (4,580 types) with the two queries of tool/live_check/gitlab: 134,016 lines -> 421, live check passes.
• GraphQLCodeGenerator.usedTypes(schema, documents) and generateTypesFile(schema, only: ...) for use outside the builder.

Tests: test/prune_types_test.dart (collection, generation, config, builder across documents), test/prune_types_compile_test.dart (compiles and runs pruned code, strict and legacy). Fast 364, compile 6.