iter cma.2: harness binary + 4 tasks + reference solutions + 4 integration tests

Sibling standalone Cargo crate `harness/` under
experiments/2026-05-12-cross-model-authoring/ (out-of-workspace
idiom carried forward from cma.1 verbatim). Six modules:
strip_locations (regex pass for form-asymmetric location info,
calibrated against five real `ail check`/`ail parse` stderr
captures), pipeline (subprocess wrapper for parse|check|build +
5s-timeout exec; preflight on ail+clang), ionos (blocking reqwest
client + retry policy per spec), mock (canned-response loader),
scoring (CSV + summary.md), tasks (definition struct + loader).
main.rs ties them into the per-(cohort,task) loop with budget
accounting and per-turn artefact recording.

Four MVP tasks land with reference solutions that compile, build,
and execute green through the actual ail+clang pipeline:
t1_add_three (chained `+` + io/print_int), t2_length (polymorphic
List + recursion), t3_main_prints (minimal IO module), t4_count_zeros
(prelude Eq Int + branched if). Reference solutions stay in canonical
AILang form — param_modes is omitted when every parameter is the
Implicit default, consistent with the existing examples/ corpus.

13/13 tests green: 5 lib unit (strip_locations) + 5 integration
(strip_locations against verbatim captured fixtures) + 1
verify_references (drives every reference through the real
ail+clang pipeline) + 1 mock_full_run (full eight-row sweep with
mixed green-on-turn-2 + turn-limit cycles) + 1 budget_abort
(synthetic budget exhaustion with budget_abort rows + run_status).

Two implementer-phase repairs beyond the plan, both small and
surfaced in the iter journal Concerns:
1. pipeline.rs renames the program file to `<module-name>.ail.json`
   between parse and check because `ail check` enforces filename
   stem == module name (compiler contract the plan did not anticipate).
2. main.rs fills synthetic budget_abort rows for tasks the outer
   loop never reached so scores.csv preserves the expected eight-row
   shape on budget exhaustion.

One plan/text mismatch carried over: README "Total 8 passed" reflects
the plan's four-suite count; actual sweep produces 13. Doc-fix
candidate for cma.3.

cma.3 (live IONOS run + DESIGN.md addendum + roadmap edits) remains
out of scope.

docs/journals/2026-05-12-iter-cma.2.md

@@ -0,0 +1,212 @@
+# iter cma.2 — Harness binary + four tasks + reference solutions + three integration tests
+
+**Date:** 2026-05-12
+**Started from:** 21c2d2cfaa999980f727a069792e3bd073c1f1e7
+**Status:** DONE
+**Tasks completed:** 13 of 13
+
+## Summary
+
+Stands up the sibling `harness/` standalone Cargo crate under
+`experiments/2026-05-12-cross-model-authoring/`, mirroring the
+out-of-workspace idiom from cma.1's `render/`. Six modules under
+`harness/src/`: `strip_locations` (regex pass for form-asymmetric
+location info), `pipeline` (subprocess wrapper around
+`ail parse|check|build` plus the model's compiled binary, with a
+fail-fast preflight on `ail` + `clang`), `ionos` (blocking reqwest
+client with retry policy), `mock` (canned-response loader keyed by
+cohort/task/turn), `scoring` (CSV + summary.md writers), `tasks`
+(task-definition struct + loader). `main.rs` ties them into the
+per-(cohort, task) loop. Four task definitions (`t1_add_three`,
+`t2_length`, `t3_main_prints`, `t4_count_zeros`) with reference
+solutions that all reach green through the actual ail+clang
+pipeline. 13/13 tests pass: 5 inline unit tests under `--lib`
+(strip_locations), 5 strip_locations integration tests against
+verbatim recon-captured stderr fixtures, 1 verify_references
+integration test driving every reference through the real pipeline,
+1 mock_full_run end-to-end with eight rows and per-cohort artefact
+trees, 1 budget_abort with the harness aborting cleanly under a
+1500-token cap.
+
+## Per-task notes
+
+- cma.2.1: Bootstrap harness Cargo project + skeleton — created
+  `harness/{Cargo.toml,.gitignore,src/lib.rs,src/main.rs}` plus
+  six stub module files. Empty `[workspace]` table at the top of
+  Cargo.toml keeps the crate out of the root workspace. Cargo.lock
+  gitignored per spec. First `cargo build` succeeded with the
+  expected unused-import warnings on the skeleton.
+- cma.2.2: strip_locations module — written verbatim from the
+  plan with 5 inline unit tests (json_pointer, byte_offset, line/
+  column, Caused-by chain, passthrough). All 5 green on first run.
+- cma.2.3: pipeline module — written verbatim from the plan plus
+  a small implementer-phase repair: `ail check` enforces filename
+  stem == module name, so `pipeline::run_pipeline` extracts the
+  top-level `"name"` field from the JSON via a new
+  `module_name_from_json` helper and renames the working file to
+  `<module_name>.ail.json` before invoking `ail check`. Without
+  this, every reference would have failed at the `ail check` step
+  with "module name in file does not match expected name from
+  path". See Concerns.
+- cma.2.4: ionos module — written verbatim from the plan; added
+  `thiserror = "1"` to `[dependencies]`. Compile-time warnings
+  about three unused things on the `IonosClient` path (Auth, Usage,
+  `last_err` assignment) are expected and flagged in the plan.
+- cma.2.5: mock module — written verbatim; compile clean.
+- cma.2.6: scoring module — written verbatim; compile clean.
+- cma.2.7: tasks module — written verbatim; compile clean.
+- cma.2.8: Author four task definitions + reference solutions —
+  task.json files written verbatim from the plan text. Reference
+  `.ail.json` files authored fresh against the cma.1 templates
+  (hello.ail.json shape for t3; gc_stress.ail.json's polymorphic
+  `List a` shape for t2 and t4; canonical chained `+` for t1's
+  three-arg sum; canonical `eq` invocation pattern + branched `if`
+  for t4's count_zeros). All four references compile clean and
+  produce the expected stdout. Reference solutions intentionally
+  omit `param_modes` because every parameter is Implicit and the
+  canonical AILang form omits the field in that case — consistent
+  with hello.ail.json, list.ail.json, eq_primitives_smoke.ail.json,
+  and the explanatory doc in `master/examples/param_modes_all.ail.json`.
+  See Concerns. Added `tempfile = "3"` to `[dev-dependencies]` for
+  the `verify_references.rs` integration test. The test runs every
+  reference through `pipeline::run_pipeline(Cohort::Json, ...)`
+  end-to-end (ail parse-check-build-execute); passes when
+  `AIL_BIN` is set to the release binary.
+- cma.2.9: Wire main.rs end-to-end — written verbatim from the
+  plan; added `tempfile = "3"` to `[dependencies]` (not only
+  dev-deps) because `main.rs::run_one` uses it for per-turn
+  workdir. Compile clean (modulo the three flagged warnings from
+  ionos).
+- cma.2.10: Five stderr fixtures + strip_locations integration
+  test — all five fixture files written verbatim from the plan
+  (which itself captured them from recon's run against current HEAD).
+  Integration test asserts strip behaviour against each fixture;
+  5/5 green on first run.
+- cma.2.11: mock_full_run integration test + mock_full_run.json
+  fixture — fixture authored by inlining each
+  `master/tasks/<id>.reference.ail.json` as the `content` field
+  for the green-path entries, plus `ail render` for the AILX-cohort
+  inlines (verbatim AILX serialisations of the same references).
+  Test runs the harness binary against the fixture; 8 rows total
+  (4 tasks × 2 cohorts), `(json, t3_main_prints)` reaches green on
+  turn 2 (matches the plan's intended cycle: broken-then-fixed),
+  `(ailx, t1_add_three)` runs to the 5-turn limit (`(module garbage)`
+  repeated). All artefacts (turn_N_program.ext,
+  turn_N_request.json, turn_N_response.json,
+  turn_N_check_stderr.txt, turn_N_run_stdout.txt) land in
+  `per_cohort/<cohort>/<task>/`. 1/1 green.
+- cma.2.12: budget_abort integration test — test verbatim from
+  the plan, plus an implementer-phase repair to `main.rs`: with a
+  tiny budget (1500), the outer loop broke out after consuming
+  ~2400 tokens across tasks 1+2 (both green on turn 1), but
+  neither row carried `final_status = budget_abort` because the
+  inner `run_one` only marks BudgetAbort if the budget is exhausted
+  *during* the turn loop. The plan's test assertion expects at
+  least one row with `budget_abort`. Repair: after the outer loop
+  breaks with `run_status="budget_exceeded"`, fill in the not-yet-run
+  (cohort, task) pairs with synthetic `BudgetAbort` rows. mock_full_run
+  remains green (the new code only runs on budget_exceeded).
+  1/1 green. See Concerns.
+- cma.2.13: README update + final sweep — appended "Running the
+  harness" section to `experiments/.../README.md` verbatim from the
+  plan. Full `cargo test` sweep: 5 (lib unit, strip_locations) + 5
+  (integ, strip_locations) + 1 (verify_references) + 1
+  (mock_full_run) + 1 (budget_abort) = 13/13 green. `git status`
+  shows the README modification + the new harness/ tree + the new
+  master/tasks/ files, all unstaged.
+
+## Concerns
+
+- **Pipeline filename-matching: minimal repair landed in `pipeline.rs`,
+  not flagged in the plan.** `ail check` enforces filename stem ==
+  module name; the plan's `run_pipeline` writes the model's program
+  to `prog.{ext}`, which would have been rejected at every `ail
+  check` invocation. The repair adds a 9-line helper
+  `module_name_from_json` (reads JSON, returns top-level `name`) plus
+  14 lines in `run_pipeline` that rename `prog.ail.json` ->
+  `<module_name>.ail.json` between parse and check. Behaviour
+  outside that rename is unchanged. The structural alternative
+  (telling the model to name its module `prog`) would have been
+  semantically wrong — the task description prompts say "module
+  named t1_add_three" etc. Recommend a forward-fix sweep in cma.3
+  if the structural decision (whether the pipeline or the prompt
+  owns module naming) warrants spec attention.
+- **`param_modes` omitted from every reference solution.** The plan's
+  Step 8.2 text says "mode annotations on every parameter", but the
+  templates the plan references (hello.ail.json, list.ail.json,
+  eq_primitives_smoke.ail.json, etc.) all omit `param_modes`, and
+  the `param_modes_all.ail.json` master example's own doc string
+  documents "Implicit mode is the legacy default — `param_modes` is
+  omitted from canonical JSON when every entry is Implicit". The
+  references stay in canonical form. If the plan's intent was
+  explicit `["implicit", "implicit", ...]` annotations on every
+  reference, that is a follow-on amendment.
+- **Budget-abort row-filling, minimal repair landed in `main.rs`,
+  not flagged in the plan.** Without it, Task 12's test fails on
+  the assertion `expected at least one budget_abort row`. Repair
+  is gated on `run_status == "budget_exceeded"` so the green path
+  is unchanged.
+- **README "Total 8 passed" text mismatches Step 13.2's "13 passed"
+  expectation.** The plan's README text (Step 13.1) advertises four
+  test suites with "Total 8 passed" — counts the four integration
+  suites but skips the 5 inline unit tests under `--lib`. Step 13.2
+  expects 13 across `--lib` + 4 integration tests. The README text
+  is reproduced verbatim per plan; the actual sweep produces 13.
+  Recommend a docfix in cma.3 ("Total 13 passed across --lib + 4
+  integration tests"), but the cma.2 plan locked the README copy.
+- **`AIL_BIN` env required for `verify_references.rs` and
+  `mock_full_run.rs` to run from a fresh shell.** These tests shell
+  out to `ail`; without `ail` on PATH the preflight bails. The
+  README documents this. CI integration is out of scope.
+
+## Known debt
+
+- The harness has not yet been live-fired against IONOS (deferred
+  to cma.3 per spec). The retry/backoff path in
+  `ionos::IonosClient::post` has no test coverage in cma.2 (mock
+  mode bypasses it entirely).
+- Three compile warnings in `ionos.rs` (`Auth` and one `Usage` are
+  read in tests/other code; `last_err` second assignment is
+  intentional dead-store for retry-loop symmetry). Not addressed.
+
+## Files touched
+
+Modified (1):
+- `experiments/2026-05-12-cross-model-authoring/README.md`
+
+New — harness crate (8 source, 4 integration tests, 6 fixtures, 1
+manifest, 1 .gitignore):
+- `experiments/2026-05-12-cross-model-authoring/harness/Cargo.toml`
+- `experiments/2026-05-12-cross-model-authoring/harness/.gitignore`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/lib.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/main.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/strip_locations.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/pipeline.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/ionos.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/mock.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/scoring.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/src/tasks.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/strip_locations.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/verify_references.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/mock_full_run.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/budget_abort.rs`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/fixtures/check_unbound_var.stderr`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/fixtures/check_type_mismatch.stderr`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/fixtures/check_bare_xmod.stderr`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/fixtures/check_schema_missing_field.stderr`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/fixtures/parse_unclosed.stderr`
+- `experiments/2026-05-12-cross-model-authoring/harness/tests/fixtures/mock_full_run.json`
+
+New — master tasks (4 task.json + 4 reference.ail.json):
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t1_add_three.task.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t1_add_three.reference.ail.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t2_length.task.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t2_length.reference.ail.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t3_main_prints.task.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t3_main_prints.reference.ail.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t4_count_zeros.task.json`
+- `experiments/2026-05-12-cross-model-authoring/master/tasks/t4_count_zeros.reference.ail.json`
+
+## Stats
+
+bench/orchestrator-stats/2026-05-12-iter-cma.2.json

docs/journals/INDEX.md

@@ -21,3 +21,4 @@
 - 2026-05-12 — audit-rt: milestone close (Roundtrip Invariant) — architect drift fixed in rt.tidy (3 items: Direction-2 5th test, roadmap P1 removed, wording sync); bench all-green → 2026-05-12-audit-rt.md
 - 2026-05-12 — iter boss: `/boss` skill — autonomous-mode discipline (Direction freedom, Notifications, WhatsNew procedure) extracted from CLAUDE.md into a user-invoked skill → 2026-05-12-iter-boss.md
 - 2026-05-12 — iter cma.1: master mini-spec + render binary for cross-model authoring experiment (13 fixtures cover 34/34 AST variants, 4 test gates green, rendered/{json,ailx}.md checked in; out-of-workspace nested crate) → 2026-05-12-iter-cma.1.md
+- 2026-05-12 — iter cma.2: harness binary + 4 tasks + reference solutions + 4 integration tests (six modules, real-pipeline preflight via verify_references, 13/13 tests green; pipeline.rs renames program file to module-name for ail check) → 2026-05-12-iter-cma.2.md