Add auto-incrementing version number to front matter

Computes version as 1.0.N where N is the commit count since the v1.0
tag. Passed as an AsciiDoc attribute to all build targets (PDF, EPUB,
HTML).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: happi

Makefile

@@ -1,4 +1,5 @@
 ASSET_CHAPTERS = $(shell find chapters -type f)
+VERSION = 1.0.$(shell git rev-list v1.0..HEAD --count)
 
 .PHONY: all pdf pdf-a4 pdf-publish epub html docker docker-build clean serve
 
@@ -41,6 +42,7 @@ beam-book-a4.pdf: style/pdf-online-theme.yml style/pdf-theme.yml chapters/opcode
 	-a source-highlighter=rouge \
 	-a rouge-style=pastie \
 	-a rouge-linenums-mode=table \
+	-a version=$(VERSION) \
  	online-book.asciidoc -o $@
 
 # Print-ready 6×9 for PoD
@@ -55,6 +57,7 @@ beam-book-publish.pdf: style/custom-print-highlight-theme.yml style/pdf-publish-
 	-a source-highlighter=rouge \
 	-a rouge-style=pastie \
 	-a rouge-linenums-mode=table \
+	-a version=$(VERSION) \
  	print-book.asciidoc -o $@ --trace
 
 # EPUB version
@@ -66,6 +69,7 @@ beam-book.epub: chapters/opcodes_doc.asciidoc epub-book.asciidoc book.asciidoc c
 	-a config=./style/ditaa.cfg \
 	-a source-highlighter=rouge \
 	-a rouge-style=pastie \
+	-a version=$(VERSION) \
 	epub-book.asciidoc -o $@ --trace
 
 
@@ -76,7 +80,8 @@ html: chapters/contributors.txt $(ASSET_CHAPTERS)
 	  -o site/index.html online-book.asciidoc --trace \
 	  -a source-highlighter=rouge \
 	  -a rouge-style=thankful_eyes \
-	  -a rouge-linenums-mode=table
+	  -a rouge-linenums-mode=table \
+	  -a version=$(VERSION)
 	rsync -R code/*/*.png site
 
 code/book/ebin/generate_op_doc.beam: code/book/src/generate_op_doc.erl

book.asciidoc

@@ -54,7 +54,7 @@ under the Creative Commons license. This printed edition is provided for conveni
 For more information on the Creative Commons license, visit:
 link:https://creativecommons.org/licenses/by/4.0/[].
 
-First Edition, 2025
+First Edition, 2025 — Version {version}
 ISBN: 978-91-531-4253-9
 [.text-center]
 © 2025 Erik Stenman.