derstandard: mark items as seen on display, auto-prune at 200

- items command now marks ALL returned URLs as seen (not just fetched)
- Auto-prunes seen file to 200 entries (removes oldest)

bin/derstandard

@@ -57,6 +57,15 @@ mark_seen() {
   fi
 }
 
+prune_seen() {
+  # Keep only last 200 entries
+  local count=$(wc -l < "$SEEN_FILE" 2>/dev/null | tr -d ' ')
+  if [ "$count" -gt 200 ]; then
+    local excess=$((count - 200))
+    tail -200 "$SEEN_FILE" > "${SEEN_FILE}.tmp" && mv "${SEEN_FILE}.tmp" "$SEEN_FILE"
+  fi
+}
+
 is_seen() {
   grep -qF "$1" "$SEEN_FILE" 2>/dev/null
 }
@@ -74,16 +83,21 @@ case "${1:-}" in
     
     feed=$(fetch_feed "$max")
     
-    # Build items list
+    # Build items list, mark all as seen, only display unseen (unless --all)
     while IFS=$'\t' read -r title url; do
       if $show_all || ! is_seen "$url"; then
         printf '%s\t%s\n' "$title" "$url"
       fi
+      # Mark as seen regardless of display
+      mark_seen "$url"
     done < <(
       titles=$(echo "$feed" | grep -oP '<title>\K[^<]+' | tail -n +2 | decode_entities)
       urls=$(echo "$feed" | grep -oP '<link>\K[^<]+' | grep "derstandard.at/story")
       paste <(echo "$titles") <(echo "$urls") 2>/dev/null | head -"$max"
     )
+    
+    # Prune to max 200 entries
+    prune_seen
     ;;
   article)
     [ -z "${2:-}" ] && { echo "Usage: derstandard article <url>"; exit 1; }
@@ -102,6 +116,7 @@ case "${1:-}" in
       # Mark as seen
       mark_seen "$url"
     done
+    prune_seen
     ;;
   urls)
     fetch_feed "${2:-50}" | grep -oP '<link>\K[^<]+' | grep "derstandard.at/story"