Reindent to the canonical stroustrup style

Whitespace only -- `git diff -w` is empty. TODO.md 2.3 recorded that the
tree mixed hard tabs and space indents within the same functions;
tests/aksl_capture.h was the worst of it, with the assertion macros
space-indented and everything around them tabbed.

The style is the one libakerror standardised on and the one AGENTS.md
already describes: Emacs cc-mode "stroustrup", c-basic-offset 4,
indent-tabs-mode on, tab-width 8. A correct file is a fixed point of
indent-region under those settings, and the tree is one now -- a second
pass produces no diff.

scripts/reindent.el is that pass, checked in so "correct" is something
you can run rather than something you have to remember. It is not
clang-format and deliberately so: AGENTS.md forbids introducing one
without discussion, and this is a good illustration of why. cc-mode
indents every declaration in akstdlib.h one level for the extern "C" { }
wrapping the file body, so the script sets inextern-lang to 0 -- a
cc-mode offset with no clang-format equivalent, and without it the first
run moved 364 lines in the wrong direction.

Its own commit, no behaviour change, and the suite is green either side.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/reindent.el

@@ -0,0 +1,25 @@
+;; Canonical reindent: Emacs cc-mode "stroustrup", c-basic-offset 4,
+;; indent-tabs-mode on, tab-width 8. A correct file is a fixed point of this.
+;;
+;; inextern-lang is set to 0 because akstdlib.h wraps its whole body in
+;; extern "C" { }, and cc-mode otherwise indents every declaration in the file
+;; one level for it. That is a real cc-mode behaviour rather than a bug, but it
+;; is not the house style and not what the file looked like before.
+;;
+;; AGENTS.md forbids introducing clang-format, and this is why the tool that
+;; decides what "correct" means has to be the same engine the author's editor
+;; runs: this offset is not something clang-format could be made to agree with.
+(require 'cc-mode)
+(setq-default indent-tabs-mode t)
+(setq-default tab-width 8)
+(setq c-default-style "stroustrup")
+(dolist (file command-line-args-left)
+  (find-file file)
+  (c-mode)
+  (setq indent-tabs-mode t
+        tab-width 8
+        c-basic-offset 4)
+  (c-set-offset 'inextern-lang 0)
+  (indent-region (point-min) (point-max))
+  (when (buffer-modified-p) (save-buffer))
+  (kill-buffer))