feat(lotus): sendNotificationType=none turns the call-start notification off (cinny #295)

The widget intent presets default sendNotificationType to "notification",
and the URL param could only switch it to ring/notification, so the host
had no way to say "don't notify". In persistent voice channels and space
rooms that notification carries an @room mention: every member got a
highlighted ping (and phone push) whenever a moderator joined first, and
other clients showed it as a missed call.

`sendNotificationType=none` now clears it after the presets are applied.
Unit test added.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/UrlParams.test.ts

@@ -305,6 +305,19 @@ describe("UrlParams", () => {
       });
     });
 
+    it("[lotus] sendNotificationType=none turns the preset notification off", () => {
+      expect(
+        computeUrlParams(
+          "?intent=start_call&widgetId=1234&parentUrl=parent.org&sendNotificationType=none",
+        ).sendNotificationType,
+      ).toBeUndefined();
+      expect(
+        computeUrlParams(
+          "?intent=start_call&widgetId=1234&parentUrl=parent.org",
+        ).sendNotificationType,
+      ).toBe("notification");
+    });
+
     it("accepts join_existing", () => {
       expect(
         computeUrlParams(

src/UrlParams.ts

@@ -523,6 +523,14 @@ export const computeUrlParams = (search = "", hash = ""): UrlParams => {
     ...properties,
     ...intentPreset,
     ...pickBy(configuration, (v?: unknown) => v !== undefined),
+    // [lotus] `sendNotificationType=none` turns the intent preset's
+    // notification off. The host passes it for persistent voice channels and
+    // space rooms, where a call start must not @room-ping every member
+    // (LotusGuild/cinny#295). pickBy above drops undefined, so it can't be
+    // expressed as a plain override.
+    ...(parser.getParam("sendNotificationType") === "none"
+      ? { sendNotificationType: undefined }
+      : {}),
   };
 };