COD-133 fix header WS status indicator + typing lag from v1.1.15 merge

The upstream v1.1.15 merge spliced upstream's transport-object indicator
body onto local's _connectionStatus-based _updateConnectionIndicator()
without defining `transport`, so every transport.* reference threw
ReferenceError on any queued state. That hid the "WS" status and, because
_reliableSend() updates the indicator before _drainSession(), made every
keystroke skip immediate delivery (input flushed only on the 2s sweep =
typing lag).

- Rewrite _updateConnectionIndicator() to show the terminal WebSocket
  transport from _wsState (WS / HTTP / WS… / Offline), falling back to the
  SSE _connectionStatus only on the idle dashboard.
- Only annotate a backlog (· N queued) above 4 bytes so normal typing no
  longer flickers "sending 1B" on each key press.
- test/connection-indicator.test.ts (new): transport labels, the >4B
  threshold, an exhaustive never-throws guard for the ReferenceError, and
  the _reliableSend -> _drainSession invariant (typing-lag guard).
- test/input-send-order.test.ts: reconcile to local's durable input layer
  (the prior coalescing-fallback tests had been failing since 1255e28).

test/input-send-order.test.ts

@@ -0,0 +1,159 @@
+/**
+ * @fileoverview Input dispatch ordering for the durable, acknowledged delivery
+ * layer (`CodemanApp._sendInputAsync` → `_reliableSend` → `_drainSession`).
+ *
+ * Local replaced the upstream best-effort "coalescing fallback queue" with the
+ * durable per-(clientId, seq) layer in commit 1255e28 (docs/reliable-input-
+ * delivery.md). This suite verifies the client-side ordering guarantees of that
+ * layer: each input is a distinct seq-tagged frame, delivered in order over the
+ * WebSocket when open, serialized over HTTP POST when not, and only dropped on a
+ * server ACK (HTTP 2xx). Exactly-once application is covered server-side in
+ * test/reliable-input-dedup.test.ts; the header transport indicator ("WS"/"HTTP")
+ * is covered in test/connection-indicator.test.ts.
+ *
+ * Loaded via `vm` with a stubbed context (no jsdom).
+ */
+import { readFileSync } from 'node:fs';
+import { performance } from 'node:perf_hooks';
+import { resolve } from 'node:path';
+import vm from 'node:vm';
+import { describe, expect, it, vi } from 'vitest';
+
+function loadCodemanAppClass() {
+  const constants = readFileSync(resolve(import.meta.dirname, '../src/web/public/constants.js'), 'utf8');
+  const source = readFileSync(resolve(import.meta.dirname, '../src/web/public/app.js'), 'utf8');
+  const context = vm.createContext({
+    console,
+    performance,
+    setInterval: vi.fn(),
+    clearInterval: vi.fn(),
+    setTimeout,
+    clearTimeout,
+    requestAnimationFrame: vi.fn(),
+    HTMLCanvasElement: class HTMLCanvasElement {},
+    WebSocket: { OPEN: 1 },
+    fetch: (...args: Parameters<typeof fetch>) => global.fetch(...args),
+    document: { addEventListener: vi.fn() },
+    localStorage: {
+      length: 0,
+      key: vi.fn(),
+      getItem: vi.fn(),
+      setItem: vi.fn(),
+      removeItem: vi.fn(),
+    },
+    window: { addEventListener: vi.fn(), removeEventListener: vi.fn() },
+    MobileDetection: {},
+  });
+  vm.runInContext(`${constants}\n${source}\nglobalThis.__CodemanApp = CodemanApp;`, context);
+  return (context as { __CodemanApp: new () => unknown }).__CodemanApp;
+}
+
+const CodemanApp = loadCodemanAppClass();
+
+async function waitForCalls(calls: unknown[], count: number) {
+  for (let i = 0; i < 50; i++) {
+    if (calls.length >= count) return;
+    await new Promise((r) => setTimeout(r, 0));
+  }
+}
+
+type Frame = { t: string; d: string; seq: number; cid: string };
+type PostBody = { input: string; seq: number; clientId: string };
+
+type App = {
+  _sendInputAsync: (sessionId: string, input: string, opts?: { useMux?: boolean }) => void;
+  _pendingDeliveries: Map<string, Array<{ seq: number; data: string; sentAt: number }>>;
+  _ws: { readyState: number; send: (data: string) => void } | null;
+  _wsSessionId: string | null;
+  activeSessionId: string | null;
+};
+
+function makeApp(): App {
+  const app = Object.create((CodemanApp as { prototype: object }).prototype) as App & Record<string, unknown>;
+  app._clientId = 'c-test';
+  app._seqCounters = new Map();
+  app._pendingDeliveries = new Map();
+  app._postDraining = new Set();
+  app._persistReliableState = vi.fn();
+  app._persistReliableNow = vi.fn();
+  app._updateConnectionIndicator = vi.fn();
+  app.clearPendingHooks = vi.fn();
+  app.activeSessionId = 'session-1';
+  app.isOnline = true;
+  app._connectionStatus = 'connected';
+  app._ws = null;
+  app._wsSessionId = null;
+  return app as unknown as App;
+}
+
+describe('durable input delivery — send ordering', () => {
+  it('delivers rapid input as distinct ordered seq frames over an open WebSocket (no coalescing)', () => {
+    const app = makeApp();
+    const frames: Frame[] = [];
+    app._ws = { readyState: 1, send: (d: string) => frames.push(JSON.parse(d)) };
+    app._wsSessionId = 'session-1';
+
+    app._sendInputAsync('session-1', 'a');
+    app._sendInputAsync('session-1', 'b');
+    app._sendInputAsync('session-1', 'c');
+
+    // Each keystroke is its own frame, in seq order — never merged into "abc".
+    expect(frames.map((f) => f.d)).toEqual(['a', 'b', 'c']);
+    expect(frames.map((f) => f.seq)).toEqual([1, 2, 3]);
+    expect(frames.every((f) => f.t === 'i' && f.cid === 'c-test')).toBe(true);
+  });
+
+  it('POSTs queued input one frame at a time in seq order when no socket is open', async () => {
+    const app = makeApp();
+    const calls: PostBody[] = [];
+    const completions: Array<() => void> = [];
+    global.fetch = vi.fn(async (_url, init) => {
+      calls.push(JSON.parse(String(init?.body)) as PostBody);
+      await new Promise<void>((r) => completions.push(r));
+      return new Response('{}', { status: 200 });
+    });
+
+    app._sendInputAsync('session-1', 'a');
+    app._sendInputAsync('session-1', 'b');
+
+    // Serialized: only the first frame is in flight until its 2xx ACK lands.
+    await waitForCalls(calls, 1);
+    expect(calls.map((c) => c.input)).toEqual(['a']);
+
+    completions.shift()?.(); // ACK 'a'
+    await waitForCalls(calls, 2);
+    expect(calls.map((c) => c.input)).toEqual(['a', 'b']);
+    expect(calls.map((c) => c.seq)).toEqual([1, 2]);
+
+    completions.shift()?.();
+    await waitForCalls(calls, 2);
+  });
+
+  it('leaves a frame queued (unacked) when HTTP delivery fails', async () => {
+    const app = makeApp();
+    const calls: PostBody[] = [];
+    global.fetch = vi.fn(async (_url, init) => {
+      calls.push(JSON.parse(String(init?.body)) as PostBody);
+      return new Response('busy', { status: 503 });
+    });
+
+    app._sendInputAsync('session-1', 'a');
+    await waitForCalls(calls, 1);
+    await new Promise((r) => setTimeout(r, 0));
+
+    // 5xx is not an ACK — the frame must survive for the sweep/reconnect to retry.
+    expect(app._pendingDeliveries.get('session-1')).toHaveLength(1);
+    expect(app._pendingDeliveries.get('session-1')?.[0].data).toBe('a');
+  });
+
+  it('drops a frame addressed to a vanished session (404) instead of retrying forever', async () => {
+    const app = makeApp();
+    global.fetch = vi.fn(async () => new Response('gone', { status: 404 }));
+
+    app._sendInputAsync('session-1', 'a');
+    await new Promise((r) => setTimeout(r, 0));
+    await new Promise((r) => setTimeout(r, 0));
+
+    expect(app._pendingDeliveries.get('session-1')).toBeUndefined();
+  });
+});