feat(rag): pgvector knowledge base with API and LLM tools

- services/rag: knowledge_docs store — vector search via the shared
  embedder (HNSW index, graceful ILIKE fallback), list/delete scoped to
  the user, search intentionally global for the single-user deployment
- gateway: GET/POST /knowledge/docs, DELETE /knowledge/docs/:id,
  POST /knowledge/search
- plugins/knowledge: knowledge_search and knowledge_ingest tools so the
  persona can save and recall information mid-conversation
- main: migrations, store wiring, plugin registration

backend/services/gateway/api/handlers_more.go

@@ -258,8 +258,7 @@ func (r *Router) sessionExportHandler(w http.ResponseWriter, req *http.Request)
 	}
 }
 
-func (r *Router) imageAnalyzeHandler(w http.ResponseWriter, req *http.Request) {
-	if req.Method != "POST" { writeJSON(w, 405, M{"error": "POST required"}); return }
+func (r *Router) imageAnalyzeHandler(w http.ResponseWriter, req *http.Request) {	if req.Method != "POST" { writeJSON(w, 405, M{"error": "POST required"}); return }
 	if r.deps.Vision == nil { writeJSON(w, 503, M{"error": "vision not available"}); return }
 	var body struct {
 		ImageURL    string `json:"image_url"`
@@ -305,3 +304,58 @@ func (r *Router) hostExecHandler(w http.ResponseWriter, req *http.Request) {
 		"command": body.Command,
 	})
 }
+
+// ===== Knowledge Base =====
+
+func (r *Router) knowledgeDocsHandler(w http.ResponseWriter, req *http.Request) {
+	if r.deps.Knowledge == nil { writeJSON(w, 503, M{"error": "knowledge base unavailable"}); return }
+	uid := r.userID(req)
+	switch req.Method {
+	case "GET":
+		docs, err := r.deps.Knowledge.List(req.Context(), uid, 50)
+		if err != nil { writeJSON(w, 500, M{"error": err.Error()}); return }
+		writeJSON(w, 200, M{"docs": docs})
+	case "POST":
+		var body struct {
+			Title   string `json:"title"`
+			Content string `json:"content"`
+		}
+		json.NewDecoder(req.Body).Decode(&body)
+		if body.Content == "" { writeJSON(w, 400, M{"error": "missing content"}); return }
+		doc, err := r.deps.Knowledge.Ingest(req.Context(), uid, body.Title, body.Content)
+		if err != nil { writeJSON(w, 500, M{"error": err.Error()}); return }
+		writeJSON(w, 201, M{"doc": doc})
+	default:
+		writeJSON(w, 405, M{"error": "method not allowed"})
+	}
+}
+
+func (r *Router) knowledgeDocItemHandler(w http.ResponseWriter, req *http.Request) {
+	if r.deps.Knowledge == nil { writeJSON(w, 503, M{"error": "knowledge base unavailable"}); return }
+	if req.Method != "DELETE" { writeJSON(w, 405, M{"error": "method not allowed"}); return }
+	idStr := strings.TrimPrefix(req.URL.Path, "/api/v1/knowledge/docs/")
+	var id int64
+	if _, err := fmt.Sscanf(idStr, "%d", &id); err != nil || id <= 0 {
+		writeJSON(w, 400, M{"error": "invalid id"})
+		return
+	}
+	if err := r.deps.Knowledge.Delete(req.Context(), r.userID(req), id); err != nil {
+		writeJSON(w, 404, M{"error": err.Error()})
+		return
+	}
+	writeJSON(w, 204, nil)
+}
+
+func (r *Router) knowledgeSearchHandler(w http.ResponseWriter, req *http.Request) {
+	if r.deps.Knowledge == nil { writeJSON(w, 503, M{"error": "knowledge base unavailable"}); return }
+	if req.Method != "POST" { writeJSON(w, 405, M{"error": "POST required"}); return }
+	var body struct {
+		Query string `json:"query"`
+		TopK  int    `json:"top_k"`
+	}
+	json.NewDecoder(req.Body).Decode(&body)
+	if body.Query == "" { writeJSON(w, 400, M{"error": "missing query"}); return }
+	docs, err := r.deps.Knowledge.Search(req.Context(), r.userID(req), body.Query, body.TopK)
+	if err != nil { writeJSON(w, 500, M{"error": err.Error()}); return }
+	writeJSON(w, 200, M{"docs": docs, "total": len(docs)})
+}

backend/services/gateway/api/router.go

@@ -13,6 +13,7 @@ import (
 
 	"git.yeij.top/AskaEth/Cyrene_v2/services/ai-core/model"
 	"git.yeij.top/AskaEth/Cyrene_v2/services/gateway/store"
+	"git.yeij.top/AskaEth/Cyrene_v2/services/rag"
 )
 
 // --- Interfaces for injected services ---
@@ -96,6 +97,14 @@ type VisionAnalyzer interface {
 	AnalyzeImage(ctx context.Context, prompt, imageRef string) (string, error)
 }
 
+// KnowledgeStorer manages the knowledge base.
+type KnowledgeStorer interface {
+	Ingest(ctx context.Context, userID, title, content string) (*rag.Document, error)
+	Search(ctx context.Context, userID, query string, topK int) ([]rag.Document, error)
+	List(ctx context.Context, userID string, limit int) ([]rag.Document, error)
+	Delete(ctx context.Context, userID string, id int64) error
+}
+
 // ChatStorer persists chat sessions and messages.
 type ChatStorer interface {
 	CreateSession(ctx context.Context, id, userID, title string) (*store.Session, error)
@@ -123,6 +132,7 @@ type Dependencies struct {
 	AutomationEng AutomationEngine
 	Reminders    *ReminderStore
 	Vision       VisionAnalyzer
+	Knowledge    KnowledgeStorer
 	PluginList   []map[string]string
 }
 
@@ -184,6 +194,11 @@ func (r *Router) setupRoutes() {
 	// Message search & session export
 	r.mux.HandleFunc("/api/v1/messages/search", r.authMW(r.messageSearchHandler))
 
+	// Knowledge base
+	r.mux.HandleFunc("/api/v1/knowledge/docs", r.authMW(r.knowledgeDocsHandler))
+	r.mux.HandleFunc("/api/v1/knowledge/docs/", r.authMW(r.knowledgeDocItemHandler))
+	r.mux.HandleFunc("/api/v1/knowledge/search", r.authMW(r.knowledgeSearchHandler))
+
 	// Image analysis
 	r.mux.HandleFunc("/api/v1/images/analyze", r.authMW(r.imageAnalyzeHandler))