Pure policy, no wiring yet. 12 unit tests, 584 green overall, 0 warnings.
- **Machine starvation** buys less work: 60 → 30 fps first, then 1080 → 720. The vertical tier has no
resolution step — its floor *is* its only geometry.
- **Upload congestion** buys fewer bits: `current − max(0.5, current × lossFraction)`, floored at
3.0 Mbps (16:9) / 4.0 (vertical). Resolution is deliberately not a bandwidth lever: 1080p30 and
720p60 cost the same, so dropping pixels at an unchanged bitrate relieves nothing.
- **Budgets** as ruled: three steps for a 1920-wide start, one for 720 and vertical. 15 s of evidence,
30 s cooldown, ambiguous evidence does nothing at all.
- **Recovery** is `allowClimb`, default off (the one-way ruling): the machine carries its ceiling from
construction, climbs one step after 180 s of clean windows, and a climb followed by a relapse inside
120 s freezes the session at the low value — one flap pair is proof enough.
Inputs are the poster's own counters (`PumpStalls`, `PumpDrops`, `AvgRenderMs`, `EncoderDrops`), not a
throughput reading: `StreamHealth.CurrentBitrate` is ffmpeg's *encoded output* rate and sits at target
even while the socket is gagging, so it cannot size a step.
