Migrate ordinary I/O from confined file helpers

internal/config/party_resolution.go

@@ -24,7 +24,7 @@ func resolvePartyInput(input ResolvedInputFile) (ResolvedParty, error) {
 		path = filepath.Join(filepath.Dir(configPath), path)
 	}
 	path = filepath.Clean(path)
-	raw, err := fileops.ReadRegularFile(path, maxPartyDocumentBytes)
+	raw, err := fileops.ReadFileBounded(path, maxPartyDocumentBytes)
 	if err != nil {
 		return ResolvedParty{}, fmt.Errorf("read party input %q: %w", path, err)
 	}