fix(calendar-sync): run the sync from a timer instead of the agenda hook

The hourly timer armed itself from org-agenda-mode-hook, so a session where
I never opened the agenda never synced at all. After a reboot that is every
session until the first agenda call. I found it with all three calendar
files still frozen at the pre-reboot write, five hours stale.

The deferral had a real reason. Feed URLs behind :secret-host live in
authinfo.gpg, and starting at load would prompt for a passphrase on a cold
gpg-agent. The cost was worse than what it bought.

A user timer owns the schedule now, every ten minutes.
calendar-sync-auto-start defaults to nil so the editor no longer arms its
own. scripts/calendar-sync-run is the batch entry point, and it blocks
until every calendar leaves the syncing state. The pipeline is asynchronous
end to end, so a batch Emacs that returns early exits zero having written
nothing.

Installing it on a machine that resolves its feeds through :secret-host
surfaced two bugs the inline-url machine could never show:

- cj/auth-source-secret-value called auth-source-search behind nothing but
  a declare-function, which quiets the compiler and loads nothing. An
  interactive Emacs always has auth-source in by the time anyone calls, so
  the omission stayed invisible until a batch -Q sync died on a void
  function. The require is guarded on fboundp. An unconditional one reloads
  auth-source over whatever is already there, which replaced a caller's
  stubbed search mid-call and sent an existing test out to the real
  authinfo.

- A synchronous failure in one calendar aborted the whole loop. The async
  callbacks record their own failures, but they never run when the error
  lands before a process starts. Resolving a :secret-host feed signals
  outright on a cold agent. Failures are contained per calendar now, so one
  bad feed no longer costs the other two.

A failed row prints the reason it recorded. Batch Emacs discards the
*Messages* buffer the interactive path logs to, so without it the journal
shows only "error", with no way to tell a cold agent from a revoked token.

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/test-calendar-sync--sync-dispatch.el b/tests/test-calendar-sync--sync-dispatch.el
index 22deeef0..9b12b167 100644
--- a/tests/test-calendar-sync--sync-dispatch.el
+++ b/tests/test-calendar-sync--sync-dispatch.el
@@ -77,5 +77,44 @@ than crashing."
       (should (equal (list cal) ics-calls))
       (should (null api-calls)))))
 
+(ert-deftest test-calendar-sync--sync-dispatch-error-leaf-signal-is-contained ()
+  "Error: a syncer that signals marks the calendar failed instead of propagating.
+
+Resolving a `:secret-host' feed reads authinfo.gpg, and a cold gpg-agent makes
+that signal a `file-error' before any process starts — so the failure arrives
+synchronously, where the async callbacks that normally record a failure never
+run."
+  (let ((failed '())
+        (calendar-sync--calendar-states (make-hash-table :test 'equal)))
+    (cl-letf (((symbol-function 'calendar-sync--sync-calendar-ics)
+               (lambda (_) (signal 'file-error '("Decryption failed"))))
+              ((symbol-function 'calendar-sync--mark-sync-failed)
+               (lambda (name reason) (push (cons name reason) failed))))
+      (calendar-sync--sync-calendar
+       '(:name "google" :url "https://x/y.ics" :file "/tmp/c.org"))
+      (should (equal "google" (car (car failed)))))))
+
+(ert-deftest test-calendar-sync--sync-all-continues-past-a-failing-calendar ()
+  "Error: one calendar's synchronous failure does not stop the ones after it.
+
+This is the whole cost of leaving the signal uncontained: on a machine whose
+feeds resolve through authinfo, the first calendar's decryption error aborted
+the entire run, so calendars that would have synced fine never got the chance."
+  (let ((synced '())
+        (calendar-sync--calendar-states (make-hash-table :test 'equal))
+        (calendar-sync-calendars
+         '((:name "bad" :url "https://x/a.ics" :file "/tmp/a.org")
+           (:name "good" :url "https://x/b.ics" :file "/tmp/b.org"))))
+    (cl-letf (((symbol-function 'calendar-sync--sync-calendar-ics)
+               (lambda (cal)
+                 (if (equal (plist-get cal :name) "bad")
+                     (signal 'file-error '("Decryption failed"))
+                   (push (plist-get cal :name) synced))))
+              ((symbol-function 'calendar-sync--mark-sync-failed)
+               (lambda (&rest _) nil))
+              ((symbol-function 'message) (lambda (&rest _) nil)))
+      (calendar-sync--sync-all-calendars)
+      (should (equal '("good") synced)))))
+
 (provide 'test-calendar-sync--sync-dispatch)
 ;;; test-calendar-sync--sync-dispatch.el ends here