fix(review): WS state machine, per-tab supersede key, backoff, dot CSS (PR #149)

- _wsState now transitions through the full lifecycle: _connectWs() sets
  'connecting', ws.onopen (inside the this._ws === ws guard) sets 'connected',
  _disconnectWs() resets to 'disconnected' — the connection chip's "WS" state
  was previously unreachable (stuck on "WS…"/"HTTP" forever).
- WS registry supersede is now keyed per TAB: the upgrade URL sends
  cid = clientId + ':' + per-page nonce (reusing the constructor's page UUID),
  while input frames keep the bare browser clientId for seq dedup — two
  tabs/windows on one session coexist instead of 4010-evicting each other in a
  perpetual 5s ping-pong; a genuine same-tab reconnect still supersedes.
- Exponential backoff engages: _disconnectWs() no longer zeroes
  _wsReconnectAttempts (it's called at the top of _connectWs, so every retry
  replanned at attempt 0 → ~0ms tight reconnect loop during outages); onopen
  resets the counter on success.
- styles.css: add .connection-dot.connected (green) and .connection-dot.fallback
  (yellow) — both states rendered an invisible dot (no rule existed).
- Remove smuggled dead code: resolveMonitorRowLabels/CodemanMonitorLabels
  (COD-122, no consumer, referenced test doesn't exist) and the never-written
  _wsLastClose/_wsInputSendCount/_httpFallbackSendCount diagnostics.
- Tests: new test/ws-state-lifecycle.test.ts drives the REAL
  _connectWs/onopen/onclose/timer cycle (state transitions, escalating backoff
  delays, composite cid on the upgrade URL); registry two-tab coexistence test;
  static check that every emitted connection-dot class has a styles.css rule.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/web/public/constants.js

@@ -126,38 +126,6 @@ function shouldAutoWrapTabs(input) {
   return scrollWidth > clientWidth + 1;
 }
 
-// COD-122: Monitor "Tmux Sessions" row label policy. A row carries up to three
-// identifiers — the tab name (user-facing L1 label), the tmux session name
-// (e.g. "codeman-1fac7304"), and the agent (Claude/Codex) session id. The tab name
-// must win as the primary label; the other two are secondary metadata shown only
-// when known and not redundant with the primary, so the row degrades gracefully
-// when identifiers are missing.
-function resolveMonitorRowLabels(input) {
-  const clean = (v) => (typeof v === 'string' ? v.trim() : '');
-  const tabName = clean(input && input.tabName);
-  const storedName = clean(input && input.storedName);
-  const muxName = clean(input && input.muxName);
-  const agentId = clean(input && input.agentSessionId);
-  const sessionId = clean(input && input.sessionId);
-
-  // Tab name is the L1 label; fall back through the persisted mux name → tmux name
-  // → a generic placeholder so the primary is never blank.
-  const primary = tabName || storedName || muxName || 'session';
-
-  const secondaries = [];
-  // tmux name — skip when it's already serving as the primary fallback (no dup).
-  if (muxName && muxName !== primary) {
-    secondaries.push({ kind: 'tmux', label: muxName });
-  }
-  // agent session id — show only when genuinely known: non-empty, not the codeman
-  // sessionId placeholder (claudeSessionId is seeded with the session id until a
-  // real agent message arrives), and not redundant with the primary label.
-  if (agentId && agentId !== sessionId && agentId !== primary) {
-    secondaries.push({ kind: 'agent', label: agentId });
-  }
-  return { primary, secondaries };
-}
-
 // COD-134 — Terminal WebSocket reconnect policy.
 //
 // Decide what to do after a terminal WebSocket closes, given the close `code`
@@ -188,9 +156,6 @@ if (typeof window !== 'undefined') {
   window.CodemanTabOverflow = {
     shouldAutoWrapTabs,
   };
-  window.CodemanMonitorLabels = {
-    resolveMonitorRowLabels,
-  };
   window.CodemanWsReconnect = {
     plan: planWsReconnect,
   };