Merge remote-tracking branch 'origin/calendar-support' into feature-gap

# Conflicts:
#	development/vimwiki-gap.md

development/_common.sh

@@ -290,6 +290,20 @@ reset_dirs() {
   done
 }
 
+# ensure_calendar_vim — clone calendar-vim into dev dir for testing
+ensure_calendar_vim() {
+  local repo="$DEV_DIR/calendar-vim"
+  if [[ -d "$repo/.git" ]]; then
+    return
+  fi
+  if ! command -v git >/dev/null 2>&1; then
+    log "git not found — skipping calendar-vim"
+    return 1
+  fi
+  log "cloning https://github.com/mattn/calendar-vim.git → $repo"
+  git clone --depth 1 https://github.com/mattn/calendar-vim.git "$repo" >/dev/null 2>&1
+}
+
 seed_wiki() {
   if [[ "${NUWIKI_DEV_NO_SEED:-0}" == "1" ]]; then
     log "NUWIKI_DEV_NO_SEED=1 — skipping wiki seed (using $WIKI_DIR as-is)"