Drives the REAL session.resume -> _make_agent -> AIAgent path (eager_build)
through tui_gateway.server.handle_request against a real seeded state.db in
an isolated HERMES_HOME — no mocks. Three scenarios from the live report:
deleted provider falls back to default, renamed provider heals, and a legacy
canonical Bot Chat (no follow_profile_config marker) follows the profile's
current config.
A/B verified: all 3 FAIL on origin/main with the reported
"resume failed: Unknown provider '<name>'"; 3/3 pass with the salvaged
fixes + backfill.
c680f12fda