No per-frame allocations in the 'doesn't connect' marks (t87)

docs/PROJECT_MAP.md

@@ -288,10 +288,10 @@ Pipes, pumps and outlets: each joined line holds one liquid as a count, not as g
 Per-tick machine work: steam engines, fans, belts, filters, screw conveyors (machinesTick).
 - functions: engineIntake, fanBlow, machinesTick
 
-### src/sim/joins.js (125 lines)
+### src/sim/joins.js (134 lines)
 Travel-directed transport ends. Precomputed probes; world/plan queries allocate nothing. End indices stay geometric: left/right, or up/down for vertical screws.
 - functions: pieceEnds, joinCandidate, endJoin, pieceJoins, endAt, joinIsDrop, joinSnap, nearMiss
-- variables: JOIN_ENDS, NO_PIECE
+- variables: JOIN_ENDS, NO_PIECE, NEAR_MISS_VIEW
 
 ### src/sim/conveyors.js (213 lines)
 How belts, filters and screw conveyors move what is on or in them. What rests on a belt or filter rides along: the whole stack standing on the carrying surface steps one cell toward d together (belts run front of the line first, so the way ahead is clear). If a powder grain is blocked, the load above it stands still and the belt slips underneath. A filter's own material drops through it instead, unless it is already full.

docs/agent-log.md

@@ -4,6 +4,17 @@ What agents have done, newest first. Add an entry for every piece of work: the d
 note or request it was for, what changed, the files touched, the tests run, and anything left
 open or not verified. Keep each entry short; the git history has the details.
 
+## 2026-10-29: t87 reuse the near-miss view (Codex)
+
+- Reused one scratch view, its entry array and get/has methods in src/sim/joins.js;
+  replaced the two-row temporary array with a numeric loop. Connection rules unchanged.
+- Files: src/sim/joins.js, docs/PROJECT_MAP.md, tasks/t87* and this log. Map regenerated.
+- All 41 headless suites pass; every suite's before/after output matches excluding timings
+  (/tmp/t87-determinism.diff empty). Pixel test/play.py passes with no console errors.
+  Frozen shots/t87-{before,after}.png match exactly; inspected the after image and red marks.
+- test/t_smooth.py fails elbow/collar and ghost-preview image checks on both original and
+  refactored code, with no page errors; left those existing failures outside t87's scope.
+
 ## 2026-10-29: t83 remove old-save conversions (Codex)
 
 - Removed only spring, solid-pipe, single-material-filter and foreground-tree conversions