docs(licensing): add SPDX headers

Add SPDX copyright and license markers to repository metadata and
documentation files.

Use comment styles appropriate for git attributes, gitignore, the commit
message template, README, and justfile so license metadata is visible
without changing runtime behavior.

1 files changed, 212 insertions, 207 deletions

diff --git a/.gitignore b/.gitignore
index 1490f5d..84284bc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,207 +1,212 @@
-dist/
-testfiles/
-
-# Created by https://www.toptal.com/developers/gitignore/api/windows,linux,macos,zsh,fish,vim,emacs,git
-# Edit at https://www.toptal.com/developers/gitignore?templates=windows,linux,macos,zsh,fish,vim,emacs,git
-
-### Emacs ###
-# -*- mode: gitignore; -*-
-*~
-\#*\#
-/.emacs.desktop
-/.emacs.desktop.lock
-*.elc
-auto-save-list
-tramp
-.\#*
-
-# Org-mode
-.org-id-locations
-*_archive
-
-# flymake-mode
-*_flymake.*
-
-# eshell files
-/eshell/history
-/eshell/lastdir
-
-# elpa packages
-/elpa/
-
-# reftex files
-*.rel
-
-# AUCTeX auto folder
-/auto/
-
-# cask packages
-.cask/
-dist/
-
-# Flycheck
-flycheck_*.el
-
-# server auth directory
-/server/
-
-# projectiles files
-.projectile
-
-# directory configuration
-.dir-locals.el
-
-# network security
-/network-security.data
-
-
-### Fish ###
-fishd.*
-fish_history
-fish_variables
-config.local.fish
-
-### Git ###
-# Created by git for backups. To disable backups in Git:
-# $ git config --global mergetool.keepBackup false
-*.orig
-
-# Created by git when using merge tools for conflicts
-*.BACKUP.*
-*.BASE.*
-*.LOCAL.*
-*.REMOTE.*
-*_BACKUP_*.txt
-*_BASE_*.txt
-*_LOCAL_*.txt
-*_REMOTE_*.txt
-
-### Linux ###
-
-# temporary files which can be created if a process still has a handle open of a deleted file
-.fuse_hidden*
-
-# KDE directory preferences
-.directory
-
-# Linux trash folder which might appear on any partition or disk
-.Trash-*
-
-# .nfs files are created when an open file is removed but is still being accessed
-.nfs*
-
-### macOS ###
-# General
-.DS_Store
-.AppleDouble
-.LSOverride
-
-# Icon must end with two \r
-Icon


-
-# Thumbnails
-._*
-
-# Files that might appear in the root of a volume
-.DocumentRevisions-V100
-.fseventsd
-.Spotlight-V100
-.TemporaryItems
-.Trashes
-.VolumeIcon.icns
-.com.apple.timemachine.donotpresent
-
-# Directories potentially created on remote AFP share
-.AppleDB
-.AppleDesktop
-Network Trash Folder
-Temporary Items
-.apdisk
-
-### macOS Patch ###
-# iCloud generated files
-*.icloud
-
-### Vim ###
-# Swap
-[._]*.s[a-v][a-z]
-!*.svg  # comment out if you don't need vector files
-[._]*.sw[a-p]
-[._]s[a-rt-v][a-z]
-[._]ss[a-gi-z]
-[._]sw[a-p]
-
-# Session
-Session.vim
-Sessionx.vim
-
-# Temporary
-.netrwhist
-# Auto-generated tag files
-tags
-# Persistent undo
-[._]*.un~
-
-### Windows ###
-# Windows thumbnail cache files
-Thumbs.db
-Thumbs.db:encryptable
-ehthumbs.db
-ehthumbs_vista.db
-
-# Dump file
-*.stackdump
-
-# Folder config file
-[Dd]esktop.ini
-
-# Recycle Bin used on file shares
-$RECYCLE.BIN/
-
-# Windows Installer files
-*.cab
-*.msi
-*.msix
-*.msm
-*.msp
-
-# Windows shortcuts
-*.lnk
-
-### Zsh ###
-# Zsh compiled script + zrecompile backup
-*.zwc
-*.zwc.old
-
-# Zsh completion-optimization dumpfile
-*zcompdump*
-
-# Zsh history
-.zsh_history
-
-# Zsh sessions
-.zsh_sessions
-
-# Zsh zcalc history
-.zcalc_history
-
-# A popular plugin manager's files
-._zinit
-.zinit_lstupd
-
-# zdharma/zshelldoc tool's files
-zsdoc/data
-
-# robbyrussell/oh-my-zsh/plugins/per-directory-history plugin's files
-# (when set-up to store the history in the local directory)
-.directory_history
-
-# MichaelAquilina/zsh-autoswitch-virtualenv plugin's files
-# (for Zsh plugins using Python)
-.venv
-
-# Zunit tests' output
-/tests/_output/*
-!/tests/_output/.gitkeep
-
-# End of https://www.toptal.com/developers/gitignore/api/windows,linux,macos,zsh,fish,vim,emacs,git
+# SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>

+#

+# SPDX-License-Identifier: BSD-3-Clause

+

+dist/

+testfiles/

+

+# Created by https://www.toptal.com/developers/gitignore/api/windows,linux,macos,zsh,fish,vim,emacs,git

+# Edit at https://www.toptal.com/developers/gitignore?templates=windows,linux,macos,zsh,fish,vim,emacs,git

+

+### Emacs ###

+# -*- mode: gitignore; -*-

+*~

+\#*\#

+/.emacs.desktop

+/.emacs.desktop.lock

+*.elc

+auto-save-list

+tramp

+.\#*

+

+# Org-mode

+.org-id-locations

+*_archive

+

+# flymake-mode

+*_flymake.*

+

+# eshell files

+/eshell/history

+/eshell/lastdir

+

+# elpa packages

+/elpa/

+

+# reftex files

+*.rel

+

+# AUCTeX auto folder

+/auto/

+

+# cask packages

+.cask/

+dist/

+

+# Flycheck

+flycheck_*.el

+

+# server auth directory

+/server/

+

+# projectiles files

+.projectile

+

+# directory configuration

+.dir-locals.el

+

+# network security

+/network-security.data

+

+

+### Fish ###

+fishd.*

+fish_history

+fish_variables

+config.local.fish

+

+### Git ###

+# Created by git for backups. To disable backups in Git:

+# $ git config --global mergetool.keepBackup false

+*.orig

+

+# Created by git when using merge tools for conflicts

+*.BACKUP.*

+*.BASE.*

+*.LOCAL.*

+*.REMOTE.*

+*_BACKUP_*.txt

+*_BASE_*.txt

+*_LOCAL_*.txt

+*_REMOTE_*.txt

+

+### Linux ###

+

+# temporary files which can be created if a process still has a handle open of a deleted file

+.fuse_hidden*

+

+# KDE directory preferences

+.directory

+

+# Linux trash folder which might appear on any partition or disk

+.Trash-*

+

+# .nfs files are created when an open file is removed but is still being accessed

+.nfs*

+

+### macOS ###

+# General

+.DS_Store

+.AppleDouble

+.LSOverride

+

+# Icon must end with two \r

+Icon

+

+

+# Thumbnails

+._*

+

+# Files that might appear in the root of a volume

+.DocumentRevisions-V100

+.fseventsd

+.Spotlight-V100

+.TemporaryItems

+.Trashes

+.VolumeIcon.icns

+.com.apple.timemachine.donotpresent

+

+# Directories potentially created on remote AFP share

+.AppleDB

+.AppleDesktop

+Network Trash Folder

+Temporary Items

+.apdisk

+

+### macOS Patch ###

+# iCloud generated files

+*.icloud

+

+### Vim ###

+# Swap

+[._]*.s[a-v][a-z]

+!*.svg  # comment out if you don't need vector files

+[._]*.sw[a-p]

+[._]s[a-rt-v][a-z]

+[._]ss[a-gi-z]

+[._]sw[a-p]

+

+# Session

+Session.vim

+Sessionx.vim

+

+# Temporary

+.netrwhist

+# Auto-generated tag files

+tags

+# Persistent undo

+[._]*.un~

+

+### Windows ###

+# Windows thumbnail cache files

+Thumbs.db

+Thumbs.db:encryptable

+ehthumbs.db

+ehthumbs_vista.db

+

+# Dump file

+*.stackdump

+

+# Folder config file

+[Dd]esktop.ini

+

+# Recycle Bin used on file shares

+$RECYCLE.BIN/

+

+# Windows Installer files

+*.cab

+*.msi

+*.msix

+*.msm

+*.msp

+

+# Windows shortcuts

+*.lnk

+

+### Zsh ###

+# Zsh compiled script + zrecompile backup

+*.zwc

+*.zwc.old

+

+# Zsh completion-optimization dumpfile

+*zcompdump*

+

+# Zsh history

+.zsh_history

+

+# Zsh sessions

+.zsh_sessions

+

+# Zsh zcalc history

+.zcalc_history

+

+# A popular plugin manager's files

+._zinit

+.zinit_lstupd

+

+# zdharma/zshelldoc tool's files

+zsdoc/data

+

+# robbyrussell/oh-my-zsh/plugins/per-directory-history plugin's files

+# (when set-up to store the history in the local directory)

+.directory_history

+

+# MichaelAquilina/zsh-autoswitch-virtualenv plugin's files

+# (for Zsh plugins using Python)

+.venv

+

+# Zunit tests' output

+/tests/_output/*

+!/tests/_output/.gitkeep

+

+# End of https://www.toptal.com/developers/gitignore/api/windows,linux,macos,zsh,fish,vim,emacs,git