Same-row belt feed into an uphill low end draws as two capped ends (t67)

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

docs/DESIGN.md

@@ -500,6 +500,12 @@ above, including:
   belt one block below an uphill belt's low end also feeds it. The owner first approved a rule
   based only on shape, then found in testing that horizontal → uphill and vertical → diagonal
   didn't join the way the other pieces did.
+- **Warehouses replace the trade dock, eventually (t68, 2026-10-27).** The dock only exists to
+  get selling working for testing; the owner finds it unengaging. The plan: a warehouse at each
+  edge of the map, on indestructible ground, served by a road and trucks. Warehouses accept
+  loose grain as well as packaged goods (pallets, barrels or sacks from packaging machines).
+  Trucks matter to play, not just looks: what's waiting is collected when a truck comes, on its
+  schedule. How the player learns where the warehouses are is still open.
 
 ## Ideas not built yet
 

docs/agent-log.md

@@ -4,6 +4,16 @@ 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.
 
+## 2026-10-27: t67 belt drop drawn as two capped ends (Claude Code)
+
+- A flat belt feeding an uphill belt's low end on the same row (and two uphill slopes side by
+  side) stays joined, but grains really drop about 3 grains onto the face there, so it now
+  draws as two capped ends instead of the bridge phase 2b drew (it overlapped and stepped
+  badly). `beltDrop` in `src/render/slope-belts.js` decides it for `slopeBeltConnections` and
+  `flatBeltCaps`; the shader and `world.js` packing went back to their pre-2b versions.
+- Tests: `t_joins.js` and `t_smooth.py` drop checks updated; the existing sand test confirms
+  the same-row feed carries sand up. `python3 test/run_all.py --browser` all passed.
+
 ## 2026-10-27: t67 phase 2b, joins follow the travel direction (Claude Code + Codex)
 
 - The owner tested phase 2: horizontal → uphill and vertical-up → diagonal didn't join like the
@@ -19,9 +29,8 @@ open or not verified. Keep each entry short; the git history has the details.
   `src/render/world.js`, `src/ui/previews.js`, `tools/scenes/joins.js`, tests `t_joins.js`,
   `t_diag_screws.js`, `t_slope_belt_art.js`, `t_smooth.py`, `docs/PROJECT_MAP.md`.
 - Tests: `python3 test/run_all.py --browser` all passed.
-- Open: Codex hit its usage limit before finishing. A flat belt feeding an uphill belt on the
-  same row is joined but draws badly in the smooth look (overlapping casing, stepped edges;
-  `shots/joins-belt-drop-smooth.png`). Not playtested; determinism diff not re-run by hand.
+- Open: Codex hit its usage limit before finishing; the belt drop drawing was finished in the
+  next entry. Not playtested.
 
 ## 2026-10-27: t67 phase 2, screw conveyors follow the join rule (Claude Code + Codex)