Switch the general subagent model from opencode/deepseek-v4-pro (zen
endpoint, subject to workspace balance limits) to tinfoil/deepseek-v4-flash
(pay-per-use API, no rolling balance limit, cheaper than pro).
This completes the fleet-wide move to deepseek-flash on tinfoil: the upgrader
parent (LOOP_MODEL) and report (REPORT_MODEL) are set in upgrader.env, and
this changes the subagents. The hourly supervisor stays on glm-5.2.
Verified: tinfoil endpoint accepts deepseek-v4-flash (HTTP 200, 2.3s response).
Trial run next Friday (2026-08-21) to evaluate flash capability on the
upgrade workload; fall back to pro if it struggles on complex recipes.