Operator-side kill matrix for every LLM-driven surface. Master flag
`assistantEnabled` plus five sub-flags carve the seven surfaces:
Coach + chat, Daily Briefing + advisor, per-metric status cards,
correlation narration, Health-Score delta explainer. Defaults are
`true` so existing installs upgrade without losing affordances.
New `src/lib/feature-flags/` module exposes `getAssistantFlags()`,
`resolveAssistantFlags()` and the `AssistantDisabledError` typed
error route handlers throw to surface the 403 +
`errorCode: "assistant.disabled.<surface>"` envelope. The resolver
forces every sub-flag false when the master is off so callers never
have to compose `master && sub`.
Locks per `.planning/RESPONSE-TO-IOS-TEAM-2026-05-16.md` §3 R5:
the same matrix gates server-routed AND iOS on-device surfaces.
Migration 0065 is additive only; `app_settings` gains six boolean
columns, all default `true`, idempotent under `IF NOT EXISTS`.
Marc-André Bombeck
b68206eca4