fix(tmux): isolate sessions on a dedicated socket + raise pane nofile limit (fixes new-session crash after tmux upgrade) (#96)

* fix: isolate codeman tmux sessions

* fix(tmux): unify all sessions onto a single dedicated socket

Remove the per-session `tmuxSocket` field that recorded which tmux server
each session lived on (default vs the `codeman` socket). That field was a
persisted cache of physical reality and could drift — causing live sessions
to be wrongly marked dead ("tab shows no session found") and spawning
duplicate "Restored:" tabs.

All Codeman sessions now live on one process-wide socket (`tmux -L codeman`,
overridable via CODEMAN_TMUX_SOCKET), exposed via TmuxManager.muxSocket on
the TerminalMultiplexer interface. reconcileSessions() collapses from a
multi-socket scan (locate / re-pin / cross-socket dedup) to a single
`list-panes` query. loadSessions() strips the obsolete field from on-disk
records so it stops being written back.

Also fix two sibling bare-`tmux` call sites the unification would otherwise
leave broken (same #80 regression class — bare tmux hits the user's default
server and never finds a session on the codeman socket):
- session.ts queryTmuxWindowSize(): add `-L <socket>` (was silently falling
  back to 120x40 on re-attach, losing scrollback)
- session-routes.ts send-key (Shift+Enter / Ctrl+Enter newline): route
  through ctx.mux.muxSocket

SSH chooser scripts (tmux-manager.sh, tmux-chooser.sh) route every tmux call
through `tmux -L $CODEMAN_TMUX_SOCKET`, matching the TS default.

---------

Co-authored-by: Teigen <teigen@TeigendeMac-mini.local>

src/web/routes/session-routes.ts

@@ -652,11 +652,18 @@ export function registerSessionRoutes(
     }
 
     try {
+      // Route through the dedicated Codeman socket — bare `tmux` would target the
+      // user's default server and never find this session (same #80 regression class).
       await new Promise<void>((resolve, reject) => {
-        execFile('tmux', ['send-keys', '-H', '-t', muxName, ...hex], { timeout: 5000 }, (err) => {
-          if (err) reject(err);
-          else resolve();
-        });
+        execFile(
+          'tmux',
+          ['-L', ctx.mux.muxSocket, 'send-keys', '-H', '-t', muxName, ...hex],
+          { timeout: 5000 },
+          (err) => {
+            if (err) reject(err);
+            else resolve();
+          }
+        );
       });
     } catch (err) {
       console.error('[Server] send-key failed:', err);