Move the tools from Python to C++17 and Bazel

The scripts in use become programs run with `bazelisk run //tools:<tool>`,
and arguments follow `--`:

  amalgamate     the single-file distribution; --check only compares it
  check          licenses, convenience headers, header guards, file names,
                 versions and whether the distribution is up to date
  third-party    compares third_party/ with its archives, or writes it
  version        prints the version, or moves every place that states it
  release-notes  prints a section of the release notes
  repo-info      reports the checkout and the tools on PATH; --json writes
                 it through yyjson, with the fields of Tala's repo-info

amalgamate writes what the Python script wrote, byte for byte, except for
the time of generation. That line is gone so that the output is
deterministic and --check can compare it.

MODULE.bazel now pins the archives of third_party/ by version and sha256,
so Bazel fetches and checks them instead of a tool of ours, and Renovate
reads the versions there.

Scripts nobody used are gone: fixWhitespace, updateDocumentSnippets,
buildAndTest, and updateDocumentToC, which rewrote unrelated documents.
CheckConvenienceHeaders leaves CTest, since //tools:check runs it in CI.
The Python of tests/TestScripts stays: those are tests, not tools.

1 files changed, 43 insertions, 0 deletions

diff --git a/tools/AmalgamateMain.cpp b/tools/AmalgamateMain.cpp
new file mode 100644
index 00000000..c5e2218c
--- /dev/null
+++ b/tools/AmalgamateMain.cpp
@@ -0,0 +1,43 @@
+// Copyright (c) 2026 Progmasoft.
+// SPDX-License-Identifier: MPL-2.0 WITH AdditionRef-Progmasoft-Exception-2.0
+
+// bazelisk run //tools:amalgamate [-- --check]
+
+#include <iostream>
+#include <string_view>
+
+#include "tools/Amalgamation.hpp"
+#include "tools/Repository.hpp"
+
+int
+main(int argc, char **argv)
+{
+    using namespace Progmasoft::Catch3::Tools;
+
+    const bool check = argc == 2 && std::string_view{ argv[1] } == "--check";
+    if (argc > 2 || (argc == 2 && !check))
+    {
+        std::cerr << "usage: bazelisk run //tools:amalgamate [-- --check]\n";
+        return 2;
+    }
+    const auto root = RepositoryRoot();
+    if (!root)
+    {
+        std::cerr << "run this tool with bazelisk run\n";
+        return 2;
+    }
+    Problems problems;
+    const auto amalgamation = GenerateAmalgamation(*root, problems);
+    if (problems.empty())
+    {
+        if (check)
+        {
+            CheckAmalgamation(*root, amalgamation, problems);
+        }
+        else
+        {
+            WriteAmalgamation(*root, amalgamation, problems);
+        }
+    }
+    return Finish(problems);
+}