feat(system-utils): tint the *scratch* background a shade lighter

A buffer-local face remap lightens the *scratch* default background by cj/scratch-background-lighten percent (default 5) so it reads as the scratch buffer, applied on emacs-startup-hook. The colour math is display-dependent (verified live); the pure helper's guard contract is unit-tested.

1 files changed, 3 insertions, 1 deletions

diff --git a/todo.org b/todo.org
index d2284ff47..724f7700f 100644
--- a/todo.org
+++ b/todo.org
@@ -2421,7 +2421,9 @@ configuration (=text-config=, =diff-config=, =ledger-config=,
 ** TODO [#B] org-roam :config triggers the 15-20s refile scan synchronously at first idle :bug:solo:next:
 =modules/org-roam-config.el:78-79= — org-roam is =:defer 1=, so its :config calls =cj/build-org-refile-targets= at 1s idle, BEFORE the 5s background timer (=org-refile-config.el:144-151=); on a cold cache the 30k-file scan runs inline and freezes Emacs at first idle. Drop the call — org-roam is loaded long before the 5s timer fires. Likely a player in the filed org-capture 15-20s perf task (=[#B] Optimize org-capture target building performance=) — check both together. From the 2026-06 config audit.
 
-** TODO [#B] Scratch buffer background a shade lighter than default :feature:next:
+** DONE [#B] Scratch buffer background a shade lighter than default :feature:next:
+CLOSED: [2026-06-15 Mon]
+cj/scratch-apply-background remaps the *scratch* default background lighter (cj/scratch-background-lighten percent, default 5) via color-lighten-name, applied on the existing emacs-startup-hook. The percent is a tunable defcustom. Pure helper tested for the display-independent contract; the lightening itself is display-dependent (color-name-to-rgb), verified live in the daemon.
 Make *scratch* just-noticeably lighter than the normal background so it reads as the scratch buffer. Simplest is a buffer-local face remap on *scratch*; Craig is fine routing it through org-faces if a theme hook is wanted. The exact lightening delta is an aesthetic call to tune visually. From the roam inbox.
 ** VERIFY [#B] Stale elpa gptel shadows the local fork — likely the gptel-magit root :bug:quick:solo:next:
 Needs from Craig: can't be done standalone. I tried deleting elpa/gptel-0.9.8.5 — the fork loaded fine and gptel-magit still worked via use-package autoloads, but package activation then printed "Unable to activate gptel-magit / Required gptel-0.9.8 unavailable" on every startup, so I reverted. To remove the shadow we must also resolve gptel-magit's package dependency: either drop gptel-magit's package dep (load it via load-path like the gptel fork), or repackage the fork into .localrepo as gptel. Tell me which and I'll do it; this pairs with the gptel-magit investigation.