COD-106 shared/collaborative remote tmux sessions (window-size latest + shared badge)

Two Codeman clients attaching the same durable remote tmux session at different
viewports would fight: tmux sizes a window to the SMALLEST attached client by
default. Push `window-size latest` to the remote session config so the window
tracks the most-recently-active client instead, letting concurrent clients
coexist; surface the client count for a "shared · N" badge.

Reconciled onto upstream PR #145: #145 moved the durable remote session onto the
dedicated `-L codeman-remote` socket under a `codeman-ssh-` name and scoped every
tmux set-option PER-SESSION (`set -t <name>`, never `-g`) so a shared remote tmux
server's OTHER sessions keep their own prefix/mouse/sizing. The original COD-106
commit added `set -g window-size latest` (GLOBAL) on the old `-L codeman` socket —
a regression against #145's hardening. This commit layers the window-size feature
onto #145's structure as `set -t <name> window-size latest` (per-session, on the
codeman-remote socket). Test assertions updated to the per-session form
(remote-shared-sessions.test.ts) and the byte-identical launch-command test
(remote-ssh-options.test.ts) extended with the window-size line — which supersedes
the separate f09323c9 assertion fix (dropped: it targeted the global form and also
carried unrelated CLAUDE.md doc changes).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/remote-hosts.ts

@@ -270,9 +270,13 @@ export function parseRemoteSessionList(stdout: string): RemoteSessionInfo[] {
     const created = Number(createdStr);
     const windows = Number(windowsStr);
     if (!Number.isFinite(created) || !Number.isFinite(windows)) continue;
+    // COD-106 — `session_attached` is the CLIENT COUNT (not a 0/1 flag); >1 = shared.
+    const attachedNum = Number(attachedStr.trim());
+    const attachedClients = Number.isFinite(attachedNum) ? Math.max(0, Math.trunc(attachedNum)) : 0;
     out.push({
       name,
-      attached: attachedStr.trim() === '1',
+      attached: attachedClients > 0,
+      attachedClients,
       created: Math.trunc(created),
       windows: Math.trunc(windows),
     });

src/tmux-manager.ts

@@ -805,6 +805,13 @@ export function buildRemoteLaunchCommand(options: {
     `set -t ${remoteName} mouse off`,
     `set -t ${remoteName} prefix C-q`,
     'set -s escape-time 0',
+    // COD-106 — shared/collaborative sessions: tmux defaults to sizing a window
+    // to the SMALLEST attached client, so two Codemans at different viewports
+    // would fight (clamp to the smaller). `window-size latest` sizes to the
+    // most-recently-active client instead, so concurrent clients coexist.
+    // Per-session scoped (`set -t <name>`, matching #145's hardening) so a shared
+    // remote tmux server's other sessions keep their own sizing behavior.
+    `set -t ${remoteName} window-size latest`,
   ].join(' \\; ');
 
   // ssh runs its trailing args through the remote login shell, so the entire

src/types/session.ts

@@ -127,8 +127,10 @@ export interface SessionRemote extends RemoteSshOptions {
 export interface RemoteSessionInfo {
   /** tmux session name (always starts `codeman-`). */
   name: string;
-  /** Whether a client is currently attached to the remote session. */
+  /** Whether at least one client is currently attached to the remote session. */
   attached: boolean;
+  /** COD-106 — number of clients attached (tmux `session_attached`); >1 = shared. */
+  attachedClients: number;
   /** tmux `session_created` epoch seconds. */
   created: number;
   /** Number of windows in the remote session. */

src/web/public/session-ui.js

@@ -1858,9 +1858,15 @@ Object.assign(CodemanApp.prototype, {
     const rows = sessions.map(s => {
       const ageSecs = Math.max(0, now - (s.created || 0));
       const age = ageSecs < 3600 ? `${Math.floor(ageSecs / 60)}m` : ageSecs < 86400 ? `${Math.floor(ageSecs / 3600)}h` : `${Math.floor(ageSecs / 86400)}d`;
-      const attachedBadge = s.attached
-        ? '<span class="case-location-badge" style="background: var(--accent, #61afef);">attached</span>'
-        : '';
+      // COD-106 — show "shared · N clients" when more than one client is attached
+      // (genuinely collaborative), else a plain "attached" badge for a single client.
+      const clients = s.attachedClients != null ? s.attachedClients : s.attached ? 1 : 0;
+      const attachedBadge =
+        clients > 1
+          ? `<span class="case-location-badge" style="background: var(--warning, #e5c07b); color: #000;">shared · ${clients} clients</span>`
+          : clients === 1
+            ? '<span class="case-location-badge" style="background: var(--accent, #61afef);">attached</span>'
+            : '';
       return `
         <div class="remote-discover-item">
           <div class="remote-discover-info">