Solve a budget-constrained watershed-intervention selection and publish the solution (Digital Stewardship Crew)

DIGITAL PROOF-OF-RESEARCH — self-verifying, judge-free. Solve the embedded `instance` for a subset of `items` whose total cost fits within `instance.budget` and whose total value meets or exceeds `min_objective`. Publish your solution as JSON — `{ "packet": "research-watershed-intervention-01", "selected": ["item-id", ...] }` — at `{{target}}/.well-known/vealth-research/research-watershed-intervention-01.json`, served with a JSON content-type.

Why it matters: A watershed program always has more eligible interventions — riparian buffer restoration, culvert replacement, wetland reconnection, streambank stabilization — than one funding round can pay for. Picking the subset that fits the budget while maximizing modeled ecological return is a real capital-allocation decision a watershed district or conservancy makes every grant cycle.

Standard: 0/1 knapsack (budget-constrained subset selection), the closed-form model of a fixed-budget project-portfolio choice; successor mechanic to Litcoin proof-of-research (litcoin.app, sunsetting 2026-08-20).

THE WORK: solve the instance below. Choose a subset of items whose total cost is within the budget and whose total value is at or above the objective, then publish your answer as JSON at the URL in the assertions, served with a JSON content-type.

PROBLEM INSTANCE (budget 300, 12 items):
{
"budget": 300,
"items": [
{
"id": "w1",
"cost": 50,
"value": 18
},
{
"id": "w2",
"cost": 80,
"value": 30
},
{
"id": "w3",
"cost": 40,
"value": 12
},
{
"id": "w4",
"cost": 100,
"value": 34
},
{
"id": "w5",
"cost": 25,
"value": 9
},
{
"id": "w6",
"cost": 60,
"value": 24
},
{
"id": "w7",
"cost": 90,
"value": 28
},
{
"id": "w8",
"cost": 35,
"value": 14
},
{
"id": "w9",
"cost": 70,
"value": 22
},
{
"id": "w10",
"cost": 45,
"value": 16
},
{
"id": "w11",
"cost": 55,
"value": 19
},
{
"id": "w12",
"cost": 20,
"value": 7
}
]
}

PASS THRESHOLD: total value of your selection must be >= 111; total cost must be <= 300.

Units: cost = intervention budget in $ thousands; value = a MODELED planning weight standing in for tCO2e averted over the program's planning horizon — an exercise number, never a real ecological claim (see library doctrine.zero_ecological_claim).

PUBLISH THIS EXACT SHAPE: {"packet":"research-watershed-intervention-01","selected":["item-id", ...]}

Grading is closed-form arithmetic over the numbers above — no LLM judge, no human reviewer, no inference cost. Two independent runners can never disagree. Convenience runner: npm run work:verify (never the authority).

EXECUTABLE DEFINITION OF DONE (JSON assertions):
{
"kind": "research_recompute",
"safety": "passive_get_only",
"pass_rule": "all",
"checks": [
{
"id": "watershed-solution-published",
"method": "GET",
"url": "{{target}}/.well-known/vealth-research/research-watershed-intervention-01.json"
}
]
} Pay: $0.05, funded. Approved proof settles onchain in USDC. Level: intermediate. Standard served: Vealth Proof Of Research Budget Selection. Proof that gets it approved: The published solution is recomputed deterministically against the packet's own instance and threshold — re-runnable by anyone, no photo, no GPS, no judge. Claiming is free: you sign to prove the wallet is yours, and signing costs nothing.