fix(memory): guard provider embedding dimensions to 1536 schema (#563)

- Reject incompatible explicit provider embedding dimensions on create/update
- Ignore previously saved incompatible dimensions at runtime, fall back to 1536
- Share RequiredMemoryEmbeddingDimensions constant from store package
- Remove dimensions input from provider UI (always 1536 per pgvector schema)
- Add HTTP, runtime, and validation unit tests

Closes #548
Supersedes #410

cmd/gateway_agents.go

@@ -123,11 +123,12 @@ func buildEmbeddingProvider(
 		apiBase = memCfg.EmbeddingAPIBase
 	}
 
-	// Dimension truncation: provider settings override, default to 1536 to match pgvector schema.
+	// Dimension truncation: default to RequiredMemoryEmbeddingDimensions to match pgvector schema.
 	// Models that natively output 1536 ignore the parameter; models with larger native dims get truncated.
-	dims := 1536
-	if es != nil && es.Dimensions > 0 {
-		dims = es.Dimensions
+	dims := store.RequiredMemoryEmbeddingDimensions
+	if es != nil && es.Dimensions > 0 && es.Dimensions != store.RequiredMemoryEmbeddingDimensions {
+		slog.Warn("ignoring incompatible provider embedding dimensions for memory schema",
+			"provider", dbp.Name, "requested", es.Dimensions, "required", store.RequiredMemoryEmbeddingDimensions)
 	}
 
 	// Try registry first for the actual API key / base (handles runtime-registered providers)

cmd/gateway_agents_test.go

@@ -0,0 +1,60 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/nextlevelbuilder/goclaw/internal/store"
+)
+
+func captureEmbeddingRequest(t *testing.T, es *store.EmbeddingSettings) map[string]any {
+	t.Helper()
+
+	var requestBody map[string]any
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
+			t.Fatalf("Decode() error = %v", err)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"data":[{"embedding":[0.1,0.2]}]}`))
+	}))
+	defer server.Close()
+
+	provider := &store.LLMProviderData{
+		Name:         "embedding-provider",
+		ProviderType: store.ProviderOpenAICompat,
+		APIKey:       "test-key",
+		APIBase:      server.URL,
+		Enabled:      true,
+	}
+
+	ep := buildEmbeddingProvider(provider, es, nil, nil)
+	if ep == nil {
+		t.Fatal("buildEmbeddingProvider() = nil, want provider")
+	}
+	if _, err := ep.Embed(context.Background(), []string{"hello"}); err != nil {
+		t.Fatalf("Embed() error = %v", err)
+	}
+	return requestBody
+}
+
+func TestBuildEmbeddingProviderDefaultsTo1536Dimensions(t *testing.T) {
+	requestBody := captureEmbeddingRequest(t, nil)
+	if got := requestBody["dimensions"]; got != float64(1536) {
+		t.Fatalf("dimensions = %v, want 1536", got)
+	}
+}
+
+func TestBuildEmbeddingProviderIgnoresIncompatibleStoredDimensions(t *testing.T) {
+	requestBody := captureEmbeddingRequest(t, &store.EmbeddingSettings{
+		Enabled:    true,
+		Model:      "voyage-4-nano",
+		Dimensions: 2048,
+	})
+	if got := requestBody["dimensions"]; got != float64(1536) {
+		t.Fatalf("dimensions = %v, want fallback 1536", got)
+	}
+}