fix(agent-chat): keep Session Info rail visible across pane changes

Closed
TE
12d ago
+22-60

Problem

The Session Info rail disappeared while an output split or covered view changed the pane. Its open state remained set, but the panel was removed and re-added, producing a visible blink and leaving the rail unavailable at the narrow transition.

Change

Keep an open Session Info rail mounted whenever the Inspector feature is on. Covered views and output splits no longer suppress it; the existing overlay geometry and explicit Settings Push behavior remain unchanged, so the default rail does not claim a layout column or move the native left rail.

Validation

  • git diff --check passed.
  • python3 scripts/cmux-next/prepush-gate.py passed with no new violations.
  • Managed fleet webviews check passed on exact head 79ee08eecb94021977048eb591fd1478b7dc0503: ci-step bc6d133f0aa18e75f4c4cf3c, worker cmux10s-Mac-mini.local, focused test/chat-inspector-surfaces.test.tsx, exit code 0.
  • Local direct Bun execution was repository-guarded to the managed fleet route; no local native build was run.

Changelog

Fixed: Keep the Session Info rail visible while the pane changes layout.

Agent session: big-red