Lake banks slope down to the water instead of ending in a cliff (t96)

Digging basins to the lower rim left a 9-18 grain vertical cliff on each lake's high side
(owner screenshots, seed 766733). From each edge inward the ground now falls at most 0.7 grains
a column and is never raised above the natural surface. New no-cliff check in t_lakes.js;
world hashes re-baselined (shallow ore: 2 cells changed, on a lake bank).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/agent-log.md

@@ -15,6 +15,12 @@ open or not verified. Keep each entry short; the git history has the details.
   414 of 28,291 cells changed, all under the two new lake basins). t_lakes.py width threshold
   300 -> 150. Golden fixtures now also freeze surfY/dirtY/AMB from the previous generator.
 - Full `run_all.py --browser`: see the commit; t_smooth.py is the known flake (t99).
+- Follow-up (owner screenshots, seeds 766733/12446/23565): the lower-rim lip left a 9-18 grain
+  cliff on each lake's high side. Banks now slope (at most 0.7 grains a column inward from each
+  edge, never above natural ground); max step beside lakes is 1 on all checked seeds. New
+  t_lakes.js check "lake banks slope with no cliff" fails on the cliff version for 6 of 7 seeds.
+  Remaining 17-18 grain steps are at the trade dock's own foundation edge (seed 12446 had it
+  before this change too); not changed.
 
 ## 2026-10-29: t96 round 2 — level lakes during generation (Codex)