Function compile_frontend_from_ast_with_file_paths 

pub fn compile_frontend_from_ast_with_file_paths(
    ast: Ast,
    interner: ThreadedRodeo,
    preview_features: &PreviewFeatures,
    suppress_comptime_dbg_print: bool,
    target: &Target,
    file_paths: FxHashMap<FileId, String>,
) -> MultiErrorResult<CompileState>

Full-control variant: like compile_frontend_from_ast_with_options_full_target but additionally threads a file_id → path map into sema so @import("...") resolution can find sibling modules. The LSP needs this on the per-root compile path — parse_all_files_with_preview doesn’t populate sema’s file_paths map on its own.