feat(s36): deterministic integer-ore estimate scaling with model x effort

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0145ZKPLMVeqM47z2jxxokym

src/portfolio_optimiser/costsim.py

@@ -102,3 +102,51 @@ def _price_ore_per_1k(model: str, pricing: PricingContract) -> int | None:
     if entry is None:
         raise ValueError(f"missing price for {model}")
     return entry.ore_per_1k_tokens
+
+
+# Effort is a costsim-LOCAL what-if scenario knob (integer percent multipliers on the token ceiling).
+# HONESTY (målbilde §1): the runtime does NOT consume an effort setting today — there is no
+# `effort`/`ChatOptions` counterpart in the model-map or run path — so this is an explicit scenario
+# dimension for the what-if, never a measured runtime input.
+EFFORT_FACTORS: dict[str, int] = {"low": 70, "standard": 100, "high": 140}
+
+# The hard per-run token ceiling. A run cannot exceed it (mirrors run.py's default budget cap), so it
+# IS the honest per-run upper bound — rounds are NOT multiplied in (that double-counts the cap).
+_DEFAULT_MAX_TOKENS = 100_000
+
+
+def estimate_run_ore(
+    model: str, effort: str, pricing: PricingContract, max_tokens: int = _DEFAULT_MAX_TOKENS
+) -> int | None:
+    """Deterministic INTEGER-øre upper-bound estimate for ONE run of ``model`` at ``effort``.
+
+    ``max_tokens`` is the hard per-run ceiling → the honest per-run upper bound (rounds are not
+    multiplied in — that double-counts the cap). ``effort`` scales it by a scenario factor (see
+    ``EFFORT_FACTORS``). Returns ``None`` when ``model`` is an unpriced placeholder. Pure integer
+    math (float NOK is banned — ``ledger.py``); marked as an estimate (øvre grense), not a
+    prediction."""
+    if effort not in EFFORT_FACTORS:
+        raise ValueError(f"unknown effort {effort!r}; known: {sorted(EFFORT_FACTORS)}")
+    rate = _price_ore_per_1k(model, pricing)
+    if rate is None:
+        return None
+    scaled_tokens = max_tokens * EFFORT_FACTORS[effort] // 100
+    return scaled_tokens * rate // 1000
+
+
+def estimate_portfolio_ore(
+    model: str,
+    effort: str,
+    pricing: PricingContract,
+    *,
+    n_projects: int,
+    max_tokens: int = _DEFAULT_MAX_TOKENS,
+) -> int | None:
+    """Deterministic portfolio upper bound = ``n_projects × estimate_run_ore``. ``None`` if the
+    model is an unpriced placeholder. Fail-fast on a negative project count."""
+    if n_projects < 0:
+        raise ValueError(f"n_projects must be >= 0, got {n_projects}")
+    per_run = estimate_run_ore(model, effort, pricing, max_tokens)
+    if per_run is None:
+        return None
+    return n_projects * per_run