# SPRINT 3 — THE GAME LOOP (instructions for Opus 4.8 lanes)

*Sprint 2 verdict: the storm is real. Merged main boots into a yard with live
weather, a walking ped, a rendered sail that cascades believably, debris that
dents both cloth and player, rain that stops at the cloth, and 169/0/0 green.
What's missing is the GAME around it: you can't rig with the mouse in the shell,
can't pick up a spare, can't see loads without the console, and nothing scores
the aftermath. Sprint 3 closes the loop so a stranger could play it.*

Read THREADS.md from the last [I] entry down before starting. Two integrator
facts you must absorb: (1) main.js now passes `debris` as rig.step's 4th arg;
(2) the downdraft data is back at C's 0.3/0.18 and B's decision-3 assert
self-skips below 0.5 — item 1 below is why.

## Decisions (made)

7. **Garden HP is driven by `skyfx.rainShadowOver(bed)` during storms.**
   B and C both recommended it and they're right — at night the sun shadow is a
   number about nothing. `rig.coverageOver(bed, sunDir)` stays as the daytime
   shade readout (and becomes the heatwave scorer later). Lane A wires it.
8. **Downdraft semantics change to fraction-of-TOTAL wind speed** (B's
   preference, C's code). Gust-only semantics measurably cannot satisfy both
   the no-free-lunch bar and §7 survival (numbers in THREADS [I] 2026-07-17).
9. **`world.shedTable` is Lane A's, this sprint, first.** It gates D's §7
   hand-play and it's ~15 lines of dressing.

## Lane A — finish the shell (the sprint's spine)

In priority order:
1. **`world.shedTable`** — place `shed_01_v1.glb` + `shed_table_v1.glb`, expose
   `{pos}` (use E's `pickup_anchor` empty if present). Unblocks D immediately.
2. **Decision 2 anchor rework** (carried from Sprint 2): posts in to ~(−4.5,5.5)
   and (4.0,6.0), add p3 near (0,7), register E's tree `branch_anchor_*`
   (they carry `rating_hint`). New a.test assert: ≥3 pickable quads in 18–45 m²
   covering the bed. This also fixes B's "cascade at t=0.4 s from pre-tension
   alone" finding — the yard currently teaches the wrong lesson.
3. **Prep phase playable**: wire B's picking adapter (it exists on their branch
   contract — coordinate in THREADS) to anchor markers + hardware cycling +
   tension dial + spare purchase, with budget $80. Take B up on their offer of
   a **preview rig for live force arrows during prep** — DESIGN.md calls this
   the core teaching tool.
4. **HUD**: per-corner load bars in kN vs rating (world-anchored), wind meter +
   gust telegraph banner, garden HP (decision 7) driving E's
   plants_full/tattered/dead swaps, phase banner.
5. **Forecast card** (storm JSON summary: peak wind, gust character, change
   time — sell the dread) and **aftermath screen** (garden %, corners lost,
   hardware bill, verdict line). Enter-to-advance is fine.
6. Yard dressing completion: swap graybox house for `house_yardside_v1.glb`
   (decision 6 — read fascia_anchor_* from the GLB), fence set, washing line
   (head spins in gusts — E gave you `sway_amp` handles too, use them for the
   canopy telegraph), wheelie bin into the debris pool, gnome placed in sail
   range (`collateral_value` 25 — score it in aftermath).
7. Retitle the page — it still says M0.

## Lane B + Lane C — the downdraft semantic (JOINT, do it first, pair in THREADS)

1. **C**: `weather.core.js` — downdraft becomes a fraction of TOTAL wind speed
   (sustained + gust), keeping the own-RNG-stream determinism guarantee and the
   storm-JSON validator (rename the field if semantics change enough to warrant
   it — e.g. `downdraftOfTotal` — a silently re-meaning field is worse than a
   rename). Keep `speedAt()` horizontal.
2. **B**: re-run the 8-direction sweep at C's proposed values, re-enable the
   decision-3 assert (delete the <0.5 self-skip — it documents *gust-only*
   semantics and dies with them), confirm §7 all three legs (cheap cascades /
   twisted survives / twisted+repair survives) against the SAME data. Log the
   final constants in THREADS. Both asserts green on the same storm JSON is
   this item's definition of done.
3. **B**: sail UVs + E's `sail_weave.png` per their recipe (uv attribute,
   repeat 6×6, sRGB) — the membrane should read as fabric, and the tear decal
   strip is waiting for M3 tearing.
4. **C**: storm_03 — author a third storm between gentle and wildnight so the
   campaign has a ramp (and the forecast card has range to sell).

## Lane D — close the §7 loop by hand (gate 3)

1. The moment A posts `world.shedTable`: verify the full loop live — pick up
   spare (PickUp → Carry/CarryIdle), run it through gusts (shelter on C when
   needed), hold-E repair at the blown corner (Crank/repair, spare consumed),
   rig finishes ≥3/4. **Record the run** (SHADES.step + screenshots, or a
   screen capture) — this artifact is the sprint's definition of done.
2. Wire `StumbleBack` vs full knockdown thresholds against real storm_02 gusts
   with C's downdraft — the brace mechanic (hold C) changes the tuning you did
   pre-merge.
3. Ladder: E shipped `ladder_01_v1.glb` with base/top nodes and you have
   ClimbLadder — if fascia repairs are meant to need it (DESIGN.md says yes),
   land carry-ladder + place + climb as the stretch goal; flag early if it's
   bigger than this sprint.

## Lane E — juice pass (small)

1. Sail tear decals hookup notes for B (you shipped the atlas; write the
   two-line recipe like you did for the weave).
2. Aftermath props: broken-gnome variant (`garden_gnome_01_broken`), snapped
   fence panel — the aftermath screen wants wreckage to point at.
3. Assembled-yard contact sheet refresh once A's dressing lands (your Sprint 2
   item 4, still open — the yard finally looks like the game this week).

## Gates

```
gate 1: A-1 lands → D starts closing the loop
gate 2: B+C downdraft semantic → both physics gates green on one storm JSON
gate 3: prep→storm→aftermath playable start to finish with the mouse,
        §7 scenario ON RECORD, selftest green
```

Definition of done = gate 3. That is also the moment SHADES stops being a tech
demo — get there and the next conversation is about content (storms, sites,
the landscaper campaign), not systems.

## For John

- Nothing blocks on you this sprint. The M1 stays an asset-build box.
- When gate 3 lands you'll want to actually play it: `python3 server.py` in the
  repo, http://localhost:8801/ (or --port anything), WASD/shift/E/C/Enter.
