Bot can never be trapped in rock: nudge, retrace trail, fly out (t72)

docs/agent-log.md

@@ -4,6 +4,21 @@ 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: t72 rescue the bot from buried natural rock (Codex)
+
+- Added explored nearest/up-first nudges, a 256-point typed-array trail and messaged
+  retrace/fly-through escape. Trail update O(1), allocation-free; searches capped at 696
+  candidates per burial. Trail resets/rebuilds on load; no worldgen/save format changes.
+- Files: src/sim/{bot,world}.js, test/t_bot_rescue.{js,py}, docs/{DESIGN,TESTING,PROJECT_MAP}.md,
+  tasks/t72* and this log. Regressions failed first; all 39 headless suites pass (18 rescue checks).
+- Only browser test: python3 test/t_bot_rescue.py (messages, real keyboard escape, pixel,
+  no page errors); inspected shots/t72-{retrace,escape,open}.png. No full browser suite.
+- tools/perf.py settled/pixel before -> after: median frame interval 16.67 -> 16.67 ms;
+  CPU frame p50/p95 zoom 2: 9.71/11.34 -> 9.02/10.40 ms, zoom 6: 5.26/7.77 -> 4.19/5.01 ms.
+  Short samples show no regression, not a proven speedup. Sandbox WebGPU failed; host GPU passed.
+  Evidence: /tmp/t72-{red,headless,browser,before,after}.log and before/after JSON.
+  Owner playtest pending. No commit.
+
 ## 2026-10-29: t96 wake new-world lakes and keep trees off their banks (Codex)
 
 - Wake water after startup reset; omit whole tree candidates on wet/water-connected low banks.