feat(notify): own webhook as a full notification channel

The custom webhook could be entered but never switched on since the
notification matrix replaced the old alarm channels. It is now a third
column next to e-mail and Discord for every event and the daily summary;
bundles go out as JSON (event "digest").

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/notify_test.go

@@ -28,6 +28,14 @@ func notifyServer(t *testing.T) (*Server, *[]sentNote) {
 		sent = append(sent, sentNote{channel: "discord", to: url, text: strings.Join(lines, "\n")})
 		return nil
 	}
+	srv.notifyWebhookHook = func(url, heading string, items []notifyItem) error {
+		lines := make([]string, 0, len(items))
+		for _, it := range items {
+			lines = append(lines, it.text)
+		}
+		sent = append(sent, sentNote{channel: "webhook", to: url, text: strings.Join(lines, "\n")})
+		return nil
+	}
 	return srv, &sent
 }
 
@@ -102,6 +110,18 @@ func TestOwnChangesPauseAndChannels(t *testing.T) {
 		t.Fatalf("expected one Discord message, got %+v", *sent)
 	}
 
+	// Own webhook as a channel of its own
+	*sent = nil
+	set.Events.Watched = domain.ChannelChoice{Webhook: true}
+	_ = store.SetNotificationSettings(me.ID, set)
+	own := "https://hooks.example.com/mindsift"
+	_, _ = store.UpdateUserFull(me.ID, nil, nil, nil, nil, nil, nil, nil, &own, nil, nil)
+	sessionCall(router, "PATCH", "/api/v1/thoughts/"+task.ID, myToken, `{"priority":"normal"}`, "")
+	srv.flushNotifications(time.Now().Add(10 * time.Minute))
+	if len(*sent) != 1 || (*sent)[0].channel != "webhook" || (*sent)[0].to != own {
+		t.Fatalf("expected one webhook message, got %+v", *sent)
+	}
+
 	// Paused: nothing at all
 	*sent = nil
 	set.Paused = true
@@ -114,7 +134,7 @@ func TestOwnChangesPauseAndChannels(t *testing.T) {
 
 	// Settings round trip over the profile API
 	rec := sessionCall(router, "PATCH", "/api/v1/auth/settings", myToken, `{"notificationSettings":{"paused":false,"events":{"shared":{"email":false,"discord":true}},"dailySummary":{"enabled":true,"time":"6:5"}}}`, "")
-	if rec.Code != http.StatusOK || !strings.Contains(rec.Body.String(), `"time":"07:00"`) || !strings.Contains(rec.Body.String(), `"shared":{"email":false,"discord":true}`) {
+	if rec.Code != http.StatusOK || !strings.Contains(rec.Body.String(), `"time":"07:00"`) || !strings.Contains(rec.Body.String(), `"shared":{"email":false,"discord":true,"webhook":false}`) {
 		t.Fatalf("settings: %d %s", rec.Code, rec.Body.String())
 	}
 }