fix callback URL to use configurable public base

Separate callback URL generation from LISTEN_ADDR by introducing CALLBACK_BASE_URL with a localhost default for local development.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/ai_client/client_test.go

@@ -1,6 +1,7 @@
 package ai_client_test
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"sync/atomic"
@@ -112,3 +113,45 @@ func TestDispatch_AllRetriesFailed(t *testing.T) {
 		t.Errorf("expected attempt_openclaw = 3, got %d", updated.AttemptOpenClaw)
 	}
 }
+
+func TestDispatch_UsesCallbackBaseURL(t *testing.T) {
+	tdb := database.NewTestDB(t)
+
+	var callbackURL string
+	mockServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var payload map[string]any
+		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
+			t.Fatalf("decode payload: %v", err)
+		}
+		val, _ := payload["callback_url"].(string)
+		callbackURL = val
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer mockServer.Close()
+
+	cfg := &config.Config{
+		OpenClawURL:      mockServer.URL,
+		ListenAddr:       ":9999",
+		CallbackBaseURL:  "https://bridge.example.com/",
+	}
+
+	task := &database.Task{
+		TaskUUID:  "uuid-callback-url",
+		ThreadID:  "thread-1",
+		MessageID: "msg-callback@test.com",
+		Sender:    "user@test.com",
+		Subject:   "Callback test",
+		BodyPlain: "Hello",
+		Status:    database.StatusReceived,
+	}
+	if err := database.CreateTask(tdb.DB, task); err != nil {
+		t.Fatalf("create task: %v", err)
+	}
+
+	dispatcher := ai_client.NewDispatcher(cfg, tdb.DB)
+	dispatcher.Dispatch(task)
+
+	if callbackURL != "https://bridge.example.com/callback" {
+		t.Fatalf("expected normalized callback URL, got %q", callbackURL)
+	}
+}