COD-105 discover + attach existing remote tmux sessions (detach-not-kill)

Phase 2 of the remote-tmux arc. Discover codeman-* tmux sessions already
running on a remote host (created by the remote's own Codeman or another
instance) and attach to one this Codeman didn't launch, with detach-not-kill
ownership for non-owned sessions.

- remote-hosts.ts: listRemoteCodemanSessions (ssh, VITEST-guarded, never throws)
  + pure parseRemoteSessionList + buildRemoteListSessionsCommand. Parser splits
  on the LITERAL \t the remote tmux emits (next-3.7 does not expand \t) AND a
  real tab. toAttachedSessionRemote builds a non-owned SessionRemote; toSessionRemote
  now marks the COD-104 launch path owned:true.
- tmux-manager.ts: buildRemoteAttachCommand (sibling of buildRemoteLaunchCommand);
  buildRemoteSessionCommand selects attach vs launch by ownership. killSession gains
  a detach-not-kill early return for non-owned remote sessions: tears down only the
  LOCAL pane (kills local ssh -> remote attach detaches), NEVER issues a remote
  kill-session.
- types/session.ts: RemoteSessionInfo; SessionRemote.owned + remoteSessionName.
- schemas.ts: CreateSessionSchema.attachRemoteSession {hostId, remoteSessionName};
  fixed a pre-existing no-useless-escape lint error in the jumpHost regex.
- case-routes.ts: GET /api/remote-hosts/:hostId/sessions (explicit discovery).
- session-routes.ts: attachRemoteSession create path -> non-owned session.
- UI (index.html/session-ui.js/styles.css): explicit "Discover existing sessions"
  button + Attach action (owned:false). No auto-discover.

Verified on aa-desktop: discovered codeman-disco1, attached (attached=1, shared
view), killed local probe pane -> remote SURVIVED_DETACH (attached=0). Tests:
parse/attach-cmd/ownership unit + discovery route, session-routes + case-routes green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
(cherry picked from commit 55f5ada9db6d01518a4adf6b752e460b5df39524)

src/types/session.ts

@@ -96,6 +96,43 @@ export interface SessionRemote extends RemoteSshOptions {
   port?: number;
   remotePath: string;
   commands?: Partial<Record<RemoteCommandMode, string>>;
+  /**
+   * COD-105 — whether THIS Codeman created the remote tmux session.
+   *
+   * - `true` (default for COD-104 launched sessions): we own the remote session;
+   *   an explicit "kill" may propagate a remote `tmux kill-session`.
+   * - `false` (discovered + attached an existing remote session another Codeman
+   *   created): closing the local tab must DETACH only — we must NEVER issue a
+   *   remote `kill-session`, or we'd nuke work the remote's own Codeman (or
+   *   another instance) still relies on. See `killSession()` gate.
+   *
+   * Absent is treated as owned (legacy/COD-104 sessions persisted before this
+   * field existed were all launched by us).
+   */
+  owned?: boolean;
+  /**
+   * COD-105 — for a NON-owned (discovered + attached) session, the EXISTING
+   * remote tmux session name to `attach -t` (e.g. `codeman-disco1`). It differs
+   * from this Codeman's deterministic `codeman-<id>` name because the remote
+   * session was created elsewhere. Only meaningful when `owned === false`.
+   */
+  remoteSessionName?: string;
+}
+
+/**
+ * COD-105 — a `codeman-*` tmux session discovered on a remote host's
+ * `tmux -L codeman` socket (may have been created by the remote's own Codeman,
+ * another instance, or this one). Returned by `listRemoteCodemanSessions`.
+ */
+export interface RemoteSessionInfo {
+  /** tmux session name (always starts `codeman-`). */
+  name: string;
+  /** Whether a client is currently attached to the remote session. */
+  attached: boolean;
+  /** tmux `session_created` epoch seconds. */
+  created: number;
+  /** Number of windows in the remote session. */
+  windows: number;
 }
 
 /**