feat(emacs): Customise org-agenda

Notable features include

- Show repeater intervals.
- Custom view split into day agenda and upcoming deadlines.

users/crumb/programs/emacs/modules/syd-org.el

@@ -214,6 +214,45 @@ See https://lists.gnu.org/archive/html/emacs-orgmode/2019-07/msg00081.html."
   ;; Larger LaTeX previews.
   (plist-put org-format-latex-options :scale 1.4))
 
+(defun syd-org-init-agenda-h ()
+  (setq
+   ;; The lengths of these leaders take account for our added
+   ;; `syd-org--agenda-repeater'.
+   org-agenda-scheduled-leaders '("Sched" "S.%2dx")
+   org-agenda-deadline-leaders '("Deadl" "In%2dd" "D.%2dx")
+   org-agenda-timerange-leaders '("" ; Range within a single day.
+                                  "%2d/%2d") ; Range spanning many days.
+   ;; Hide "upcoming deadlines" until the scheduled date.
+   org-agenda-skip-deadline-prewarning-if-scheduled 'pre-scheduled
+   ;; Hide completed tasks.
+   org-agenda-skip-scheduled-if-done t)
+
+  ;; Show the repeater (the repeat interval, e.g. +1d) in repeating agenda
+  ;; entries.
+  (defun syd-org--agenda-repeater ()
+    (if (org-before-first-heading-p)
+        "-------"  ; fill the time grid
+      (format "%5s: " (or (org-get-repeat) ""))))
+
+  ;; Add `syd-org--agenda-repeater' to the agenda prefix.
+  (setcdr (assoc 'agenda org-agenda-prefix-format)
+          " %i %-12:c%?-12t%s%(syd-org--agenda-repeater)")
+
+  (setq org-agenda-custom-commands
+        '(("k" "My agenda for today"
+           ((agenda
+             ""
+             ((org-agenda-span 1)
+              (org-deadline-warning-days 0)))
+            (agenda
+             ""
+             ((org-agenda-span 7)
+              (org-agenda-start-day "+1d")
+              (org-deadline-warning-days 0)
+              (org-agenda-time-grid nil)
+              (org-agenda-entry-types '(:deadline))
+              (org-agenda-overriding-header "Upcoming deadlines"))))))))
+
 (use-package org
   :defer-incrementally
   calendar find-func format-spec org-macs org-compat org-faces org-entities
@@ -310,9 +349,11 @@ See https://lists.gnu.org/archive/html/emacs-orgmode/2019-07/msg00081.html."
       ;; ol-rmail
       ;; ol-eww
       ))
-  (add-hook 'org-load-hook
-            #'syd-org-init-popup-rules-h
-            #'syd-org-init-appearance-h)
+  (syd-add-hook 'org-load-hook
+    #'syd-org-init-popup-rules-h
+    #'syd-org-init-appearance-h)
+  (with-eval-after-load 'org-agenda
+    (syd-org-init-agenda-h))
   :config
   (require 'syd-prose)
   (syd-add-hook 'org-mode-hook