sessions: show zellij tab metadata

[dapi]

What changed

• Make make rebuild ./zelma by default before running go test ./....
• Store optional zellij tab metadata on session records: zellij_tab and zellij_tab_name.
• Show ZELLIJ_TAB in sessions list and sessions list --live table output.
• Preserve backward compatibility for old schema v1 registry files without tab metadata.
• Update skill/domain/schema docs and regression tests.

Why

The old default make target only ran tests, so local ./zelma could remain stale after source changes. Also, sessions list only showed the zellij session and pane, which made it hard to locate a detected Codex pane when multiple tabs exist in the same zellij session.

Validation

• make
• go test ./...
• python3 scripts/check_memory_bank_index.py
• git diff --check
• rg --files memory-bank >/dev/null
• rg -n "zelima|Zelima" . returned only intentional guard/glossary mentions