Commits the determinism contract RED, mirroring S3.1 (b05747a RED -> 6618f67
GREEN). The wave executor does not exist yet, so `concurrency=3` still runs the
sequential path — and the test says so precisely rather than passing vacuously:
max in-flight was 1: concurrency=3 never overlapped two projects
call sequence=[FV42 x4, RV13 x4, BRU x4]
That blocked call sequence is the proof the probe works. A test that had gone
GREEN here would have been asserting something the sequential path already
satisfies — the Spike B call-counter tautology repeating — and the plan's
escalation rule would have stopped execution.
The probe returns a coroutine yielding N times via asyncio.sleep(0) (a pure
scheduler yield, no wall clock) before delegating to the canonical body, with N
read from the prompt blob since client_factory's argument is the ROLE, not the
project id. The stream path is delegated untouched, and the subclass chain is
preserved so BudgetMiddleware still engages.
Three self-checks make it non-vacuous by construction: max-in-flight > 1,
completion order != submission order, and >= 3 distinct verdict ids. Self-check
1 asserts non-identity rather than an exact reversal — asyncio.sleep(0) is a
scheduler yield, not an ordering primitive, so demanding a specific permutation
would only add a way to fail for a reason that is not the contract.
The docstring also corrects what the repetitions guard: NOT hash-seed
nondeterminism (PYTHONHASHSEED is fixed per interpreter, so every in-process rep
shares one seed), but scheduler nondeterminism under real concurrency.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LQapztREtC2mkr5oU811pr
Add keyword-only `concurrency: int = 1` to `run_portfolio`, a module-level
`_waves` partitioner, and a fail-fast on k < 1 that precedes any project load.
The execution loop is deliberately NOT changed here. At the default k=1 every
wave holds a single project, so the wave partition reproduces the existing
`for pid in ids` order by construction — the parameter is inert until Step 3
wires the executor. The 5 tests pin exactly that: order preservation across
every k, nothing dropped or duplicated, and the k<1 raise.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LQapztREtC2mkr5oU811pr
