refactor(foundation): hygiene pass across early-init, user-constants, system-defaults, chrono-tools

Six small fixes the 2026-05-15 module-by-module re-review surfaced:

- Consolidate `user-home-dir` -- canonical defconst stays in
  early-init.el (package-archive bootstrap needs it before normal
  modules load); user-constants.el switches to a `defvar` with the
  identical `(getenv "HOME")` expression so the module still loads /
  byte-compiles standalone, but at runtime early-init's defconst
  wins.
- Drop the redundant `(autoload 'env-bsd-p ...)` line in
  system-defaults.el.  The `(eval-when-compile (require
  'host-environment))` already exposes the symbol to the byte
  compiler, and at runtime host-environment is loaded earlier in
  init.el.  Added a comment documenting the boundary.
- Convert `cj/debug-modules` and `cj/use-online-repos` from `defvar`
  to `defcustom`, with `:type`, `:group 'cj`, and a top-level
  `(defgroup cj ...)` so both show up in M-x customize.
- Name the package-archive priorities in early-init.el.  Nine new
  defconsts replace the magic numbers (200 / 125 / 120 / 115 / 100 /
  25 / 20 / 15 / 5) with one constant each, plus a header comment
  explaining the local-first ordering and the gnu > nongnu > melpa >
  melpa-stable trust ranking within each tier.
- Delete the 19-line commented-out `use-package time` world-clock
  block in chrono-tools.el.  `time-zones` immediately above is the
  active replacement; git history preserves the old config if anyone
  needs it.
- Add coverage for `cj/tmr-select-sound-file`.  Collapsed the
  prefix-arg branch into a delegation to
  `cj/tmr-reset-sound-to-default` (single reset source) and
  extracted `cj/tmr--available-sound-files` as a pure helper that
  tests directly.  9 ERT tests across Normal / Boundary / Error
  cover the available-sounds helper, the reset path, the prefix-arg
  delegation (no prompt), the normal selection path, and the
  empty-dir / missing-dir / cancel boundaries.

1 files changed, 54 insertions, 13 deletions

diff --git a/early-init.el b/early-init.el
index 49a9da92..50a1de1d 100644
--- a/early-init.el
+++ b/early-init.el
@@ -81,10 +81,18 @@
 ;; --------------------------- Use Online Repos Flag ---------------------------
 ;; set to nil to only use localrepo and local elpa-mirrors (see script directory)
 
-(defvar cj/use-online-repos t
+(defgroup cj nil
+  "Craig's personal Emacs configuration."
+  :group 'convenience
+  :prefix "cj/")
+
+(defcustom cj/use-online-repos t
   "Whether to use online package repositories in addition to local repos.
-When t, online repos are added but .localrepo has highest priority (200).
-Set to nil to use only local repos.")
+When non-nil, online repos are added but .localrepo has highest priority
+(see `cj/package-priority-localrepo' below).  Set to nil to use only
+local repos."
+  :type 'boolean
+  :group 'cj)
 
 ;; ---------------------------- Startup Performance ----------------------------
 ;; increases garbage collection threshold and turns off file-name-handler
@@ -144,40 +152,73 @@ early-init.el.")
 
 (setq package-archives nil) ;; package-archives will be added below
 
+;; Named priorities for package archives.  Local-first: project-pinned
+;; .localrepo wins outright, then the local ELPA mirrors (kept on disk
+;; via the elpa-mirror scripts), then the online archives in fallback
+;; positions.  Within each tier the order is gnu > nongnu > melpa >
+;; melpa-stable, matching the trust ranking we want for resolution.
+(defconst cj/package-priority-localrepo 200
+  "Priority for the project-pinned .localrepo archive (highest).")
+(defconst cj/package-priority-mirror-gnu 125
+  "Priority for the local GNU ELPA mirror.")
+(defconst cj/package-priority-mirror-nongnu 120
+  "Priority for the local NonGNU ELPA mirror.")
+(defconst cj/package-priority-mirror-melpa 115
+  "Priority for the local MELPA mirror.")
+(defconst cj/package-priority-mirror-melpa-stable 100
+  "Priority for the local stable MELPA mirror.")
+(defconst cj/package-priority-online-gnu 25
+  "Priority for the online GNU ELPA archive.")
+(defconst cj/package-priority-online-nongnu 20
+  "Priority for the online NonGNU ELPA archive.")
+(defconst cj/package-priority-online-melpa 15
+  "Priority for the online MELPA archive.")
+(defconst cj/package-priority-online-melpa-stable 5
+  "Priority for the online stable MELPA archive (lowest).")
+
 ;; LOCAL REPOSITORY (packages in version control)
 (when (file-accessible-directory-p localrepo-location)
   (add-to-list 'package-archives (cons "localrepo" localrepo-location) t)
-  (add-to-list 'package-archive-priorities '("localrepo" . 200)))
+  (add-to-list 'package-archive-priorities
+               (cons "localrepo" cj/package-priority-localrepo)))
 
 ;; LOCAL REPOSITORY ELPA MIRRORS
 (when (file-accessible-directory-p elpa-mirror-gnu-location)
   (add-to-list 'package-archives (cons "gnu-local" elpa-mirror-gnu-location) t)
-  (add-to-list 'package-archive-priorities '("gnu-local" . 125)))
+  (add-to-list 'package-archive-priorities
+               (cons "gnu-local" cj/package-priority-mirror-gnu)))
 
 (when (file-accessible-directory-p elpa-mirror-nongnu-location)
   (add-to-list 'package-archives (cons "nongnu-local" elpa-mirror-nongnu-location) t)
-  (add-to-list 'package-archive-priorities '("nongnu-local" . 120)))
+  (add-to-list 'package-archive-priorities
+               (cons "nongnu-local" cj/package-priority-mirror-nongnu)))
 
 (when (file-accessible-directory-p elpa-mirror-melpa-location)
   (add-to-list 'package-archives (cons "melpa-local" elpa-mirror-melpa-location) t)
-  (add-to-list 'package-archive-priorities '("melpa-local" . 115)))
+  (add-to-list 'package-archive-priorities
+               (cons "melpa-local" cj/package-priority-mirror-melpa)))
 
 (when (file-accessible-directory-p elpa-mirror-stable-melpa-location)
   (add-to-list 'package-archives (cons "melpa-stable-local" elpa-mirror-stable-melpa-location) t)
-  (add-to-list 'package-archive-priorities '("melpa-stable-local" . 100)))
+  (add-to-list 'package-archive-priorities
+               (cons "melpa-stable-local" cj/package-priority-mirror-melpa-stable)))
 
 ;; ONLINE REPOSITORIES
 ;; Added regardless of network status. If offline, package operations fail gracefully.
-;; .localrepo has highest priority (200), so reproducible installs work offline.
+;; .localrepo has highest priority, so reproducible installs work offline.
 (when cj/use-online-repos
   (add-to-list 'package-archives '("gnu" . "https://elpa.gnu.org/packages/") t)
-  (add-to-list 'package-archive-priorities '("gnu" . 25))
+  (add-to-list 'package-archive-priorities
+               (cons "gnu" cj/package-priority-online-gnu))
   (add-to-list 'package-archives '("nongnu" . "https://elpa.nongnu.org/nongnu/") t)
-  (add-to-list 'package-archive-priorities '("nongnu" . 20))
+  (add-to-list 'package-archive-priorities
+               (cons "nongnu" cj/package-priority-online-nongnu))
   (add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
-  (add-to-list 'package-archive-priorities '("melpa" . 15))
+  (add-to-list 'package-archive-priorities
+               (cons "melpa" cj/package-priority-online-melpa))
   (add-to-list 'package-archives '("melpa-stable" . "https://stable.melpa.org/packages/") t)
-  (add-to-list 'package-archive-priorities '("melpa-stable" . 5)))
+  (add-to-list 'package-archive-priorities
+               (cons "melpa-stable" cj/package-priority-online-melpa-stable)))
 
 ;; Initialize package system
 (package-initialize)