Implements the R3 design note (was design-only). Default-off; the v1 whole-graph path is
byte-identical when the flag is off (shell citizen-0 signature matches the R4 golden exactly).
- chunk-local identity keyed (seed, chunkKey, i) — same seed + chunk -> same residents,
independent of town size / visit order; home edge picked from that chunk's edges.
- windowed spawn/despawn: hook-driven via Lane B's onChunkBuilt/onChunkDisposed (sim auto-
detects and stops polling) + a camera-poll fallback that needs zero Lane B changes.
- global near-cap + mixer stagger + rig pool + impostor layer unchanged, run across live chunks.
- owner-chunk despawn (no cross-boundary re-keying); per-chunk time-of-day thinning (hours-aware).
Proven on a 9x9 fixture grid: constant far-field density (~58-129 within 70m at spawn AND 150m
out, vs v1's uniform ~12-15); deterministic (507 chunk-keyed identities re-derive from seed);
leak-free (2 full grid walks / ~380 chunk cycles -> 0 geom/tex delta, pool capped 30); budget
unchanged (near-cap 24 + 1 impostor draw, 2.31ms/frame). qa.sh --strict GREEN.
Only web/js/citizens/sim.js + web/citizens_test.html changed. Flag + shell call-site documented
in LANE_D_NOTES for Lane F to wire web/index.html.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>