fix: keep a d-set favorite from reverting to the init value on restart

wttrin-favorite-location did two jobs: a defcustom the user sets in init, and the savehist-persisted value that `d`/make-default mutated. Setting it in init (setopt) clobbered the `d` choice on every startup. So a favorite promoted with `d` reverted to the init value after a restart, and the mode-line showed the wrong location's weather. wttrin-saved-locations had the same defect.

I split the two roles. The defcustoms stay as the init-set base. New savehist-persisted runtime vars, wttrin--favorite-override and wttrin--saved-locations-runtime, hold what `d`, save, rename, remove, and the geolocation commands write. Reads go through resolvers: wttrin--favorite-location returns the override or the configured favorite, and wttrin--saved-locations overlays the runtime directory on the configured one (runtime wins on a name collision). Init and `d` now write different variables, so neither clobbers the other.

Removing a saved location that only comes from init can't delete it, since the runtime removal has nothing to touch. The command now says so instead of reporting a removal that didn't happen.

There's no automatic migration. A favorite set in init is unaffected, and a favorite set only with `d` before this version is re-set once with `d`. The README documents the behavior.

1 files changed, 12 insertions, 6 deletions

diff --git a/tests/test-wttrin-use-current-location.el b/tests/test-wttrin-use-current-location.el
index 4b61657..d7d0ea6 100644
--- a/tests/test-wttrin-use-current-location.el
+++ b/tests/test-wttrin-use-current-location.el
@@ -18,14 +18,20 @@
 (defvar test-wttrin-use-current-location--saved nil
   "Snapshot of `wttrin-favorite-location' restored in teardown.")
 
+(defvar test-wttrin-use-current-location--saved-override nil
+  "Snapshot of `wttrin--favorite-override' restored in teardown.")
+
 (defun test-wttrin-use-current-location-setup ()
-  "Snapshot `wttrin-favorite-location' and clear it."
+  "Snapshot the configured favorite and the runtime override, clearing both."
   (setq test-wttrin-use-current-location--saved wttrin-favorite-location)
-  (setq wttrin-favorite-location nil))
+  (setq test-wttrin-use-current-location--saved-override wttrin--favorite-override)
+  (setq wttrin-favorite-location nil)
+  (setq wttrin--favorite-override nil))
 
 (defun test-wttrin-use-current-location-teardown ()
-  "Restore `wttrin-favorite-location'."
-  (setq wttrin-favorite-location test-wttrin-use-current-location--saved))
+  "Restore the configured favorite and the runtime override."
+  (setq wttrin-favorite-location test-wttrin-use-current-location--saved)
+  (setq wttrin--favorite-override test-wttrin-use-current-location--saved-override))
 
 ;;; Normal Cases
 
@@ -37,7 +43,7 @@
         (cl-letf (((symbol-function 'yes-or-no-p) (lambda (&rest _) t))
                   ((symbol-function 'message) (lambda (&rest _) nil)))
           (wttrin-use-current-location))
-        (should (eq t wttrin-favorite-location)))
+        (should (eq t (wttrin--favorite-location))))
     (test-wttrin-use-current-location-teardown)))
 
 (ert-deftest test-wttrin-use-current-location-normal-decline-leaves-unchanged ()
@@ -69,7 +75,7 @@ location immediately rather than at the next scheduled fetch."
                   ((symbol-function 'wttrin--mode-line-set-placeholder)
                    (lambda () nil)))
           (wttrin-use-current-location))
-        (should (eq t wttrin-favorite-location))
+        (should (eq t (wttrin--favorite-location)))
         (should fetched))
     (test-wttrin-use-current-location-teardown)))