dsh-compaction-basic REFUSES a target at config time when the output
reservation plus headroom leave no pressure budget (resolveCompactSpec
throws TargetPressureConfigError, compactIfNeeded never runs) — it does
not clamp. The reserve comment claimed a clamp, and the geometry acted
on it: a too-small window collapsed threshold to 0 and painted a
full-width headroom band, claiming a trigger the harness never fires.
The bar now reserves nothing and paints no masks for such a window,
matching the harness. Also removes the redundant reserve comments the
review flagged and restores the dashed-border rationale the mask CSS
had displaced.
bowenliang123
fc0126992c
