No placebo buttons: accept-overhang only offered when it would help

Eric clicked accept-overhang on two boxes in a Kallax cube and got an
"overhang ✓" pill with no lane behind it. The cube's flat pile claims
11.7 of 13.25 inches of width, leaving 1.55 inches of standing lane —
acknowledging waives depth and height, never width, so nothing changed.
That opening is overfull, not overhung, and the button was a placebo.

The sheet now probes before offering: a laneless resident gets the
accept button only when acknowledging would actually land it a lane;
otherwise it's marked "no room" with the honest tooltip. Acknowledged
boxes that DID land show "▮ standing, proud" (their lane isn't
flippable — proud of the shelf is the whole point), plus the
retractable "overhang ✓". Verified against the live wall: the three
Etherfields monoliths on the tower's big row read standing-proud, the
squeezed cube residents read no-room, zero page errors.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jXZFSTZQKzAC8fqpWSz9g

data/shelf_plan.csv

@@ -0,0 +1,136 @@
+name,opening,acknowledge
+Gloomhaven,library-kallax-a1,
+History of the World,library-kallax-a1,
+Age of Renaissance,library-kallax-a1,
+Simon's Cat Card Game,library-kallax-a1,
+Skip-Bo,library-kallax-a1,
+Snappy Dressers,library-kallax-a1,
+Tem-Purr-A,library-kallax-a1,
+Everdell: The Complete Collection,library-kallax-a2,
+Bugs in the Kitchen,library-kallax-a2,
+Risk: The Lord of the Rings,library-kallax-a2,
+The Cat Game,library-kallax-a2,
+The Rocky Horror Trivia Game,library-kallax-a2,
+Utter Nonsense,library-kallax-a2,
+Dixit,library-kallax-b1,
+Flick 'em Up!,library-kallax-b1,
+Googly Eyes,library-kallax-b1,
+Meteor,library-kallax-b1,
+Mysterium,library-kallax-b1,
+Sheriff of Nottingham,library-kallax-b1,
+Sheriff of Nottingham: Merry Men,library-kallax-b1,
+Speechless,library-kallax-b2,
+Superfight,library-kallax-b2,
+The Red Dragon Inn 5: The Character Trove,library-kallax-b2,
+The Red Dragon Inn Smorgasbox,library-kallax-b2,
+Throw Throw Avocado,library-kallax-b2,
+"Before I Kill You, Mister Spy...",library-kallax-b3,
+Bluffaneer,library-kallax-b3,
+Captain Marvel: Secret Skrulls,library-kallax-b3,
+Cards Against Humanity,library-kallax-b3,
+Code Master,library-kallax-b3,
+Farkle,library-kallax-b3,
+Fluxx,library-kallax-b3,
+Give Me the Brain!,library-kallax-b3,
+Go Fish Yourself,library-kallax-b3,
+Greed Quest,library-kallax-b3,
+Jenga,library-kallax-b3,
+Joking Hazard,library-kallax-b3,
+Kill Doctor Lucky,library-kallax-b3,
+Poetry for Neanderthals,library-kallax-b3,
+Rook,library-kallax-b3,
+Scrawl,library-kallax-b3,
+"...and then, we held hands.",library-kallax-b4,
+Consentacle,library-kallax-b4,
+Kensington,library-kallax-b4,
+Mage Wars Academy,library-kallax-b4,
+Onitama,library-kallax-b4,
+Patchwork,library-kallax-b4,
+5-Minute Dungeon,library-kallax-c1,
+A Gentle Rain,library-kallax-c1,
+Artistry,library-kallax-c1,
+Artistry: Delightful Doorways Mini Expansion,library-kallax-c1,
+Blink,library-kallax-c1,
+Botany,library-kallax-c1,
+Calico,library-kallax-c1,
+Carcassonne,library-kallax-c1,
+Castle Panic,library-kallax-c1,
+Castle Panic: The Dark Titan,library-kallax-c1,
+Castle Panic: The Wizard's Tower,library-kallax-c1,
+CAT CRIMES,library-kallax-c1,
+CAT STAX,library-kallax-c2,
+Catan,library-kallax-c2,
+Catan Dice Game,library-kallax-c2,
+Catan: Junior,library-kallax-c2,
+Cosmic Encounter,library-kallax-c2,
+Dastardly Dirigibles,library-kallax-c2,
+Deadly Doodles,library-kallax-c2,
+Doctor Who: The Card Game,library-kallax-c2,
+Doctor Who: The Game of Time & Space,library-kallax-c2,
+Dragon Land,library-kallax-c2,
+Dungeon!,library-kallax-c2,
+Elite Sportz Equipment Table Top Curling,library-kallax-c2,
+Evolution: The Beginning,library-kallax-c2,
+Exploding Kittens,library-kallax-c2,
+Forbidden Island,library-kallax-c3,
+GRAVITY MAZE,library-kallax-c3,
+Guillotine,library-kallax-c3,
+Herbaceous,library-kallax-c3,
+Hold Your Breath!,library-kallax-c3,
+Huggermugger,library-kallax-c3,
+Labyrinth,library-kallax-c3,
+LASER MAZE BEAM-BENDING LOGIC GAME,library-kallax-c3,
+Machi Koro,library-kallax-c3,
+Mantis Falls,library-kallax-c3,
+Munchkin,library-kallax-c3,
+Munchkin Big Box,library-kallax-c3,
+Murder at the Manor,library-kallax-c3,
+"No Thank You, Evil!",library-kallax-c3,
+Ouija,library-kallax-c4,
+Pie Face!,library-kallax-c4,
+Rivals,library-kallax-c4,
+Robot Turtles,library-kallax-c4,
+Royals,library-kallax-c4,
+Santorini,library-kallax-c4,
+Scrabble Slam!,library-kallax-c4,
+Skylanders Portal Master,library-kallax-c4,
+Small World,library-kallax-c4,
+Sorcerer: The Game of Magical Conflict,library-kallax-c4,
+SPANC: Space Pirate Amazon Ninja Catgirls,library-kallax-c4,
+Super Mario Checkers Collector's Edition,library-kallax-c4,
+Tang Garden,library-kallax-c4,
+Terror in Meeple City,library-kallax-d1,
+The Doom That Came to Atlantic City,library-kallax-d1,
+The Office Trivia Game,library-kallax-d1,
+The Simpsons Trivia Game,library-kallax-d1,
+Ticket to Ride,library-kallax-d1,
+Verdant,library-kallax-d1,
+Völuspá,library-kallax-d1,
+Walk the Plank!,library-kallax-d1,
+Wiz-War,library-kallax-d1,
+Wiz-War (Eighth Edition),library-kallax-d1,
+Wiz-War (9th Edition),library-kallax-d1,
+Advanced Civilization,library-kallax-d2,
+Britannia,library-kallax-d2,
+Civilization,library-kallax-d2,
+Civilization: West Extension Map,library-kallax-d2,
+Diplomacy,library-kallax-d2,
+Flat Top,library-kallax-d2,
+StarForce 'Alpha Centauri': Interstellar Conflict in the 25th Century,library-kallax-d2,
+Agricola,library-kallax-d3,
+Gloomhaven: Buttons & Bugs,library-kallax-d3,
+Gloomhaven: Jaws of the Lion,library-kallax-d3,
+Sleeping Gods,library-kallax-d4,
+Sleeping Gods: Distant Skies,library-kallax-d4,
+Sleeping Gods: Primeval Peril,library-kallax-d4,
+Sleeping Gods: Tides of Ruin,library-kallax-d4,
+Etherfields,library-right-shelving-e1,yes
+Etherfields: Kittenburg Expansion,library-right-shelving-e1,yes
+Etherfields: 5th Player Expansion,library-right-shelving-e1,yes
+Etherfields: Funeral Witch Campaign,library-right-shelving-e1,yes
+Etherfields: Sphinx Campaign,library-right-shelving-e1,yes
+Etherfields: Stretch Goals – Harpy & She-Wolf Campaigns,library-right-shelving-e1,yes
+Alice is Missing,library-right-shelving-2-d1,
+Alice is Missing: Silent Falls,library-right-shelving-2-d1,
+Parsely,library-right-shelving-2-d1,
+Dark Cults,library-right-shelving-2-d1,