Araminta's ruling (PR #192 follow-up): filter keyed on rung IDENTITY via
the window's own echoed granularity_v2 — Region (incl. the orbital tile
mosaic, whose tiles are all Region-rung requests) samples NEAREST because
GPU bilinear at 204.8 km/cell reads as smoothing-over-absence; District/
Quarter keep LINEAR where cell density earns the blend. One shared helper
(_filter_for_granularity_v2) at both draw call sites; unknown/missing
wire tags fall back to LINEAR (never trusted into NEAREST). COMPOSITE_
SMOOTH survives as the independent compile-time pipeline axis — the
two-axes split is documented in the file header. Washes/border fades
untouched per the ruling. Focused suite 44/44; revert-verified (helper
hardcoded LINEAR -> exactly the three Region-NEAREST tests fail).
Tickets: T-1161
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>