Ingot molds empty themselves (no F); removing a mold returns its set metal

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

docs/agent-log.md

@@ -4,6 +4,26 @@ 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.
 
+## 2026-10-23: ingot molds need no F; removing a mold returns its metal (Claude Code, with Codex)
+
+Note: "now that the ingot molds drop the ingots, what is the purpose of F…". The owner chose no F
+on ingot molds.
+
+- `src/sim/molds.js` `ejectIngot`: when nothing over or in the mold is molten, junk and mixed
+  metal (as scrap) and plugs over the trough or frozen in the grate are written as loose grains
+  into the 4 rows under the mold; what doesn't fit waits. Slag and ash are thrown away. After a
+  drop or a clean-out the grate above is raked. Bars and the short stub work as before.
+- `collectMold` on an ingot mold only says "Ingot molds empty themselves." Bit and tank molds
+  keep F. `removeMold` (every kind) gives the set metal to the bag: whole bars as bars, the rest
+  as scrap; molten metal is left alone.
+- Text: `troughState` flaws, `info.js`, `overlays.js` (no "· F" on ingots), `pieces.js`,
+  `progress.js`, `notebook.js`, `docs/systems/stone-and-liquids.md`, `docs/DESIGN.md`.
+- Tests: `t_molds` 60 checks (F does nothing on ingots; plate, slag and rake cases now
+  automatic; junk out, mixed metal out as scrap, junk waits when blocked and while molten;
+  removal returns bars and scrap, leaves molten metal). `furnace_play.js` adapted. All 11
+  headless suites and `play.py` (122) pass.
+- Open: undoing a mold removal brings the mold back empty (its metal stays in the bag).
+
 ## 2026-10-23: compact build card top-left (Claude Code, with Codex)
 
 Note: "build tool has no info box like the other tools." The owner chose a compact card.