Why: implement the reviewed I2 increment - statistics band, structure tree
with lazy section pages, panorama center (project overview + node summary),
shared selection/filter, snapshot-consistency banner and honest states, per
the frozen contract (Dev docs/superpowers 2026-10-16, rollout section 7).
Evidence: vitest 314/314 green (14 new pure-logic tests covering capability
gate, true-zero vs unavailable stats, filter toggle, snapshot equality and
update notice, context key, selection survival, honest badges); tsc -b and
vite production build green.
Impact: new workspace entry (rdm-cockpit, gated on the seven cockpit
commands); no changes to existing surfaces; reader view and right panel
land in I3.
Refs: rollout I2
weichen