feat(lotus): io.lotus.call_summary — per-call quality readout at hangup (#143)

Tracks the local participant's LiveKit ConnectionQuality (time spent
poor/lost) and Reconnecting events for the life of the in-call view and
sends one io.lotus.call_summary { durationMs, reconnects, poorMs, verdict }
to the host on the first SFU disconnect or on teardown. Nothing is stored
or sent anywhere else. CallQualityTracker is pure and unit-tested.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/lotus/lotusCallSummary.test.ts

@@ -0,0 +1,93 @@
+/*
+Copyright 2026 Lotus Guild
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { ConnectionQuality } from "livekit-client";
+import { describe, expect, it } from "vitest";
+
+import { CallQualityTracker } from "./lotusCallSummary";
+
+const clock = (): { now: () => number; tick: (ms: number) => void } => {
+  let t = 1_000_000;
+  return {
+    now: () => t,
+    tick: (ms) => {
+      t += ms;
+    },
+  };
+};
+
+describe("CallQualityTracker", () => {
+  it("reports unknown when nothing was sampled", () => {
+    const c = clock();
+    const tr = new CallQualityTracker(c.now);
+    tr.start();
+    c.tick(60_000);
+    expect(tr.summary()).toEqual({
+      durationMs: 60_000,
+      reconnects: 0,
+      poorMs: 0,
+      verdict: "unknown",
+    });
+  });
+
+  it("is good when quality stayed fine", () => {
+    const c = clock();
+    const tr = new CallQualityTracker(c.now);
+    tr.start();
+    tr.setQuality(ConnectionQuality.Excellent);
+    c.tick(30 * 60_000);
+    expect(tr.summary().verdict).toBe("good");
+  });
+
+  it("accumulates poor time across episodes, including an open one", () => {
+    const c = clock();
+    const tr = new CallQualityTracker(c.now);
+    tr.start();
+    tr.setQuality(ConnectionQuality.Good);
+    c.tick(60_000);
+    tr.setQuality(ConnectionQuality.Poor);
+    c.tick(10_000);
+    tr.setQuality(ConnectionQuality.Good);
+    c.tick(60_000);
+    tr.setQuality(ConnectionQuality.Lost);
+    c.tick(5_000);
+    const s = tr.summary();
+    expect(s.poorMs).toBe(15_000);
+    expect(s.durationMs).toBe(135_000);
+    expect(s.verdict).toBe("fair");
+  });
+
+  it("is poor with many reconnects or mostly-poor quality", () => {
+    const c = clock();
+    const tr = new CallQualityTracker(c.now);
+    tr.start();
+    tr.setQuality(ConnectionQuality.Good);
+    for (let i = 0; i < 4; i += 1) tr.reconnect();
+    c.tick(60_000);
+    expect(tr.summary()).toMatchObject({ reconnects: 4, verdict: "poor" });
+
+    const tr2 = new CallQualityTracker(c.now);
+    tr2.start();
+    tr2.setQuality(ConnectionQuality.Poor);
+    c.tick(60_000);
+    expect(tr2.summary().verdict).toBe("poor");
+  });
+
+  it("ignores unknown samples and only starts once", () => {
+    const c = clock();
+    const tr = new CallQualityTracker(c.now);
+    tr.start();
+    c.tick(1_000);
+    tr.start();
+    tr.setQuality(ConnectionQuality.Unknown);
+    c.tick(1_000);
+    expect(tr.summary()).toMatchObject({
+      durationMs: 2_000,
+      verdict: "unknown",
+    });
+  });
+});