feat: implement rule application engine with full-text variant support, batch entry processing, and tag visualization in UI.

internal/api/handlers.go

@@ -722,3 +722,52 @@ func (h *Handler) DeleteRule(w http.ResponseWriter, r *http.Request) {
 	}
 	h.writeJSON(w, http.StatusOK, map[string]string{"message": "rule deleted"})
 }
+
+func (h *Handler) ApplyRule(w http.ResponseWriter, r *http.Request) {
+	id := chi.URLParam(r, "id")
+	rule, err := h.db.GetRule(id)
+	if err != nil {
+		h.writeError(w, http.StatusNotFound, "rule not found")
+		return
+	}
+
+	evaluator := rules.NewEvaluator()
+	matchedCount := 0
+	queuedJobs := 0
+
+	// Paginate through ALL entries in batches of 500
+	batchSize := 500
+	offset := 0
+	for {
+		entries, total, err := h.db.ListEntries(db.EntryFilter{
+			View:   "all",
+			Limit:  batchSize,
+			Offset: offset,
+		})
+		if err != nil {
+			h.writeError(w, http.StatusInternalServerError, "failed to query entries: "+err.Error())
+			return
+		}
+
+		for _, entry := range entries {
+			if evaluator.Evaluate(*rule, entry) {
+				matchedCount++
+				for _, action := range rule.Actions {
+					h.pool.Dispatch(r.Context(), action, entry, 0)
+					queuedJobs++
+				}
+			}
+		}
+
+		offset += batchSize
+		if offset >= total || len(entries) == 0 {
+			break
+		}
+	}
+
+	h.writeJSON(w, http.StatusOK, map[string]interface{}{
+		"message":       fmt.Sprintf("Rule applied to %d matching post(s). %d action(s) queued.", matchedCount, queuedJobs),
+		"matched_count": matchedCount,
+		"queued_jobs":   queuedJobs,
+	})
+}