Fog of war reveals the ground around the bot through rock (t17)

Also: board rule to write tasks from chat in our own words, task
descriptions rewritten that way, and a note on lost web-board descriptions.

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

docs/DESIGN.md

@@ -234,6 +234,10 @@ above, including:
   the bag; Ctrl+click a bag name adds it to the blow mix and Ctrl+right-click to pick-up; the menu
   is one line per material because the first version was too large.
 
+- **Fog of war also reveals the ground around the bot (t17, 2026-10-24).** About 20 grains in every
+  direction, through rock, fully clear with a soft edge. Line of sight alone hid everything inside
+  the ground, so the owner couldn't see what was around them or where to dig.
+
 ## Ideas not built yet
 
 - **Concrete**, as a stronger wall material from rubble.

docs/PROJECT_MAP.md

@@ -221,10 +221,10 @@ World state: the per-cell typed arrays, alloc(), ambient temperature by depth, w
 - functions: emit, bagCap, discover, alloc, depthU, depthY, computeAmbient, fillNoise, wakeXY, wakeHeatXY, wakeIdx, wakeHeatIdx
 - variables: W, H, N, CW, CH, NCH, mat, temp, life, flags, stamp, part, mach, digp, noiseB, airS, netId, isPow, occ, surfY, dirtY, graniteY, basaltY, magmaY, roofY, AMB, worldSeed, surfBase, underD, shallowD, lapse, BW, BH, NB, blockP, blockV, ents, bgm, flyers, ghostBlocks, ghostMolds, awake, hot, hotLvl, tick, tickStamp, machines, molds, nets, pcells, powerDirty, beltL, beltR, tubeLists, brokenMachines, ghostMachines, ghostBlocked, EV, bot, bag, bagTotal, player, seen, ledger, stats
 
-### src/sim/fog.js (35 lines)
+### src/sim/fog.js (46 lines)
 Exploration only: never changes grains or the random stream.
 - functions: fogAlloc, fogMark, fogSeen, fogInit, fogLook, fogRevealAround, fogRevealAll
-- variables: FOG, fog, FW, FH
+- variables: FOG, FOG_SENSE, fog, FW, FH
 
 ### src/sim/cells.js (176 lines)
 Cell helpers (setCell, move, enter) and the falling-sand movement of powders, liquids and gases (simMove).

docs/agent-log.md

@@ -4,6 +4,19 @@ 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.
 
+## 2026-10-24: t17 Fog of war reveals the ground around the bot (Claude Code, Codex)
+
+- `src/sim/fog.js`: `FOG_SENSE = 20`; `fogLook` also reveals every fog cell within 20 grains,
+  through rock (full to 16, fading to 20). Claude rewrote Codex's per-grain `Math.hypot` loop to
+  work per fog cell. `fogLook` cost: 0.042 → 0.043 ms (every 4 ticks).
+- `test/t_fog.js`: rock 12 grains away is seen, near the edge partly, 25 away still hidden.
+- `docs/systems/fog.md`, DESIGN.md decision. Also: `.kandown/kandown_work.md` rule to write
+  tasks from chat in our own words (no owner labels, dates or quotes); t16/t19 descriptions
+  rewritten that way; `docs/kandown.md` notes that web-board descriptions were lost.
+- Tests: `run_all.py --browser` all pass (220 `play.py` checks). `t_smooth` half-resolution failed
+  on two runs while the machine was loaded (load 6–10) and passed on the final run; timing
+  `fogLook` showed the change is not the cause. Screenshot `shots/fog-sense.png` checked.
+
 ## 2026-10-24: t19 Vacuum blow all visual (Claude Code, Codex)
 
 - The owner's description was lost in kandown; chosen in chat: bag rows light up and the card

docs/kandown.md

@@ -49,6 +49,10 @@ kandown daemon stop                  # stop that daemon
   Find it with `tasks/<id>_*.md`; don't rename it.
 - `kandown create` has no body option: write the body into the file after creating it.
 - `depends_on` blocks a move to Done until the listed tasks are done.
+- **Descriptions typed on the web board can be lost.** On 2026-10-24 the owner created t16–t19
+  on the web board with descriptions; the files were saved with a title and no body. The owner
+  believes it is a bug in the web daemon (not investigated). A task with only a title may have
+  had a description: ask the owner, then write their words under `## Context` yourself.
 
 ## A task file
 

docs/systems/fog.md

@@ -13,6 +13,10 @@ Every four ticks, 256 rays from the bot's centre reveal up to 48 grains. The las
 grains fade out. Solid and powder stop sight after a four-grain fade into their face;
 air, gas and liquid pass sight. Bars and machine voids do not block it.
 
+Each look also senses the ground around the bot through rock: every fog cell within
+`FOG_SENSE` (20 grains) of the bot is revealed, fully clear out to 16 grains and fading to
+nothing at 20, so the player can see ore and caves next to their tunnel and choose where to dig.
+
 ## Saving
 
 The fog buffer is saved and exported with the other typed arrays, without a save version