Real production incident (2026-08-29): the resource-pressure guard ratioed raw cgroup v2 memory.current (which counts reclaimable page cache) against memory.max, so a busy host with ~3GiB of page cache latched a global 503 across every model for 26 minutes even though PSI/OOM/memory.events all showed zero real pressure — the kernel would have reclaimed those pages instantly. Fix: ratio the working set (current - file) for the trip/recovery check, falling back to the raw ratio when memory.stat is missing/stale/zero (never clamping to a false zero-pressure reading).
12 new tests including direct incident reproduction (raw 95%/workingset 32% stays normal) + bug-injection round trips. Full resource-pressure + admission suites green (48/48, re-verified in this batch together with the other 3 PRs: 57/57).
Add bounded weighted admission with fair queuing, deadline and cancellation handling, exact lease accounting, and a default-shadow runtime. Keep asynchronous resource-pressure shedding as an independent safety fuse and bound request feature estimation.
