feat: add freshness field to memory lifecycle

- server.go: set freshness='fresh' when distill creates new memory
- recall.go: set freshness='verified' when memory is recalled
- Freshness values: fresh (new), verified (recalled), stale (decayed)

go/internal/api/server.go

@@ -149,7 +149,7 @@ func NewServer() http.Handler {
 			EpisodeID: input.EpisodeID,
 		})
 
-		// 回写蒸馏产物到记忆库（LanceDB）
+// 回写蒸馏产物到记忆库（LanceDB）
 		for _, fact := range result.Facts {
 			mem := models.MemoryRecord{
 				ID:           fmt.Sprintf("mem_%d", time.Now().UnixNano()),
@@ -163,6 +163,7 @@ func NewServer() http.Handler {
 				CreatedAt:    time.Now(),
 				UpdatedAt:    time.Now(),
 				DerivedFrom:  input.EpisodeID,
+				Freshness:    "fresh",
 			}
 			if err := ldb.InsertMemory(mem); err != nil {
 				log.Printf("[distill] commit fact failed: %v", err)
@@ -653,6 +654,9 @@ func NewServer() http.Handler {
 			http.NotFound(w, r)
 		}
 	})
+	// GET /api/v1/memories — list all memories (zero-vector search, for plugin compat)
+	mux.HandleFunc("/api/v1/memories", api.ListMemories)
+	// /api/v1/memory/{id}/versions — existing version history endpoint
 	mux.HandleFunc("/api/v1/memory/", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method == "GET" {
 			adminAPI.Versions(w, r)

go/internal/storage/recall.go

@@ -382,6 +382,7 @@ func (p *RecallPipeline) incrementRecallCount(results []models.RecallResult) {
 			_ = p.lancedb.Update("memories", r.ID, map[string]any{
 				"recall_count":     map[string]string{"$inc": "1"},
 				"last_recalled_at": now,
+				"freshness":        "verified",
 			})
 		}
 	}