update clang-{format,tidy}

add REUSE header, fix modelines, indent case labels

.clang-format

@@ -1,4 +1,7 @@
-# -*- mode: yaml -*-
+# SPDX-FileCopyrightText: 2022 tastytea <tastytea@tastytea.de>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # Written for clang-format 13.
 # https://releases.llvm.org/13.0.0/tools/clang/docs/ClangFormatStyleOptions.html
 ---
@@ -59,7 +62,7 @@ IncludeCategories:              # stdlib headers into own group.
     Priority: 4
 IndentAccessModifiers: false
 IndentCaseBlocks: false
-IndentCaseLabels: false
+IndentCaseLabels: true
 IndentExternBlock: NoIndent
 IndentGotoLabels: false
 IndentPPDirectives: AfterHash
@@ -117,3 +120,6 @@ UseCRLF: false
 UseTab: Never
 # WhitespaceSensitiveMacros: ['STRINGIZE', 'PP_STRINGIZE']
 ...
+
+
+# vim: set ft=yaml: -*- mode: yaml -*-

.clang-tidy

@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 tastytea <tastytea@tastytea.de>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # Written for clang-tidy 14.
 
 ---
@@ -49,5 +53,4 @@ CheckOptions:   # ↓ Clashes with static private member prefix. (static int _va
                 - { key: readability-identifier-length.MinimumVariableNameLength, value: 2      }
 ...
 
-# -*- mode: yaml; fill-column: 100; -*-
-# vim: set fenc=utf-8 tw=100 et ft=yaml:
+# vim: set tw=100 ft=yaml: -*- mode: yaml; fill-column: 100; -*-