tmux.conf sets pane-base-index 1, but dev-session.sh was
referencing panes starting at .0. All splits and send-keys
silently failed, leaving a single empty pane with no dashboard.
- tmux.conf: 256-color, mouse, sensible defaults, purple status bar
- dev-session.sh: 2-window layout (hermes TUI + timmy devloop)
- install.sh: symlinks configs into place
- Auto-attach via .zshrc on Terminal.app open