Installed inactive e2e proof: 3 replicas and repair-after-loss (ELACITY-2298) #45

From the 0.7 completion checklist in #38 (unfinished at merge time).

Prove the inactive end-to-end path on the installed product path: 3 replicas plus repair-after-loss. Source-level coverage exists; this gate closes only with installed evidence on the exact revision.

Tracked as ELACITY-2298. Depends on #44 (installed custody + chain prerequisites). Blocks #46 and #47.