roadmap: close Embedding ABI — M1 ([~]->[x]); route 3 fieldtest findings

M1 fully ratified and CLOSED: spec (grounding-check PASS) + plan
(Boss-Repaired for the module==stem fixture defect) + iter (818177d
partial+Repair / e406d07 DONE 7/7) + audit 425c4eb CLEAN + fieldtest
6a4e866 thesis-substantiated (0 bugs; clause-1 + clause-3 empirically
confirmed first-try).

3 non-blocking fieldtest findings routed to P1, ahead of M2:
- [todo] form_a.md scalar-parameter mode carve-out — docs-honesty
  tidy (friction + spec_gap#1, shared root: form_a.md's unconditional
  'every param needs own/borrow' misdirects the scalar export
  headline; scalars require bare (con Int)). Pre-existing form_a.md
  defect M1 surfaced. Settled behaviour -> tidy, no brainstorm.
- [feature] ail emit-ir --emit=staticlib — restore the Decision-5
  kernel-IR-readability affordance (add it; not narrow DESIGN.md).

INDEX line added. Next milestone (Embedding ABI — M2) has no spec ->
/boss new-milestone bounce-back.

docs/roadmap.md

@@ -129,69 +129,81 @@ work progresses.
 
 ## P1 — Next
 
-- [~] **\[milestone\]** Embedding ABI — M1: linkable artifact +
-  scalar C entrypoint + `main`-free lifecycle. First of a
-  five-milestone arc (M1–M5) that makes a compiled AILang kernel
-  callable in-process from a concurrent Rust host, so a swarm of
-  backtests over `data-server`-supplied market data runs each
-  backtest as an independent single-threaded AILang computation.
+- [x] **\[milestone\]** Embedding ABI — M1: linkable artifact +
+  scalar C entrypoint + `main`-free lifecycle — CLOSED 2026-05-18.
+  First of the five-milestone arc (M1–M5) making a compiled AILang
+  kernel callable in-process from a concurrent Rust host. Shipped:
+  additive `FnDef.export: Option<String>` (hash-stable, ~85-site
+  compile-driven thread); Form-A `(export "<sym>")` modifier
+  (round-trip-gated); check-side scalar-only+effect-free export gate
+  (`export-non-scalar-signature` / `export-has-effects` — the
+  feature-acceptance clause-3 discriminator *in code*); codegen
+  `Target::StaticLib` (suppresses `@main`+`MissingEntryMain`, emits
+  one external `@<sym>` forwarder per export, decoupled from
+  `ail_<module>_<fn>` mangling per Decision 2); CLI `ail build
+  --emit=staticlib` (`lib<entry>.a` + separate `libailang_rt.a`).
+  Coherent stop PROVEN: C host links both archives, calls the
+  scalar kernel, typed return holds. spec `51160e9` (grounding-check
+  PASS) → plan `b0bd7ef` (Repaired) → iter `818177d` (partial 1–3 +
+  Boss plan Repair: a module≠stem fixture defect, resolved Option 2)
+  + `e406d07` (DONE 4–7). Milestone-close `audit` `425c4eb` CLEAN
+  (architect clean — Invariant 1 holds semantically, lockstep
+  intact; sole `[low]` rustfmt-divergence evidence-adjudicated
+  carry-on, 1137 pre-existing tree-wide divergences prove rustfmt
+  is not a project convention; bench `check.py` exit 1 decisively
+  causally exonerated — 21/21 bench binaries `cmp`-byte-identical
+  vs pre-milestone, the two tracked-P2 noise families, NO ratify).
+  `fieldtest` `6a4e866` substantiated the thesis (0 bugs; Int+Float
+  positive E2E first-try clean = clause-1; both clause-3 rejections
+  precise+self-correcting; 3 working) — 3 non-blocking findings
+  routed to the two follow-up items directly below. Stays here
+  briefly for context; remove once stale (full record in
+  `docs/journals/INDEX.md`).
+  - context: `docs/specs/2026-05-18-embedding-abi-m1.md`;
+    `docs/specs/2026-05-18-fieldtest-embedding-abi-m1.md`;
+    `docs/journals/2026-05-18-iter-embedding-abi-m1.1.md`;
+    `docs/journals/2026-05-18-audit-embedding-abi-m1.md`
 
-  **Motivation (shared by M1–M5).** The target deployment of
-  AILang is financial-data analysis: a host (Rust, owning
-  `data-server`'s shared zero-copy cache) drives a swarm of
-  backtests; each backtest is the pure per-chunk fold AILang is
-  built for (`(State, Chunk) -> State`, the `sum_sq` loop/recur
-  shape). Today AILang is a whole-program compiler whose only
-  output channel is `io/print_str` — there is no way to invoke a
-  compiled AILang function from a host with structured arguments
-  and a typed return. That missing call surface, not the math, is
-  the entire blocker. This is a backend/packaging capability, not
-  a language feature: the language semantics do not change. Its
-  justification is strategic (this is where the language is meant
-  to run), not the standard authoring-utility gate — a deliberate,
-  user-made direction call (2026-05-18 chat).
+- [ ] **\[todo\]** form_a.md scalar-parameter mode carve-out — docs-
+  honesty tidy (M1 fieldtest friction + spec_gap, shared root).
+  `crates/ailang-core/specs/form_a.md` "Schema invariants" item 1 +
+  the Pitfalls bullet state an *unconditional* "every `(fn …)` param
+  MUST be wrapped in `(own T)`/`(borrow T)`; implicit mode is
+  rejected" — but scalars require **bare** `(con Int)` (`(own (con
+  Int))` → `use-after-consume`, `(borrow …)` →
+  `consume-while-borrowed`; bare checks `ok`). The doc the LLM reads
+  first actively misdirects M1's headline export task into a
+  body-pointing linearity diagnostic that never names the real cause.
+  Pre-existing form_a.md defect M1 made acute (the export task is the
+  first where a careful fresh author follows the mode prose for a new
+  program). Fix: state the scalar-parameter carve-out symmetrically
+  with the existing return-type carve-out (form_a.md item 1 +
+  Pitfalls), and mirror the canonical bare-scalar export-param
+  spelling in DESIGN.md §"Embedding ABI (M1)". Behaviour is settled
+  (no language/checker change) → a docs-honesty tidy in the
+  `docs-honesty-lint` class (anti-regression presence/absence pin),
+  not a brainstorm milestone. P1 — it undermines the clause-1
+  authoring ergonomics of the surface the rest of the M2–M5 arc
+  extends, so it precedes M2.
+  - context: `docs/specs/2026-05-18-fieldtest-embedding-abi-m1.md`
+    findings [friction] + [spec_gap]#1.
 
-  **Invariants (audited at every close in this arc).**
-  (1) *Clean core* — `ailang-core` / `ailang-codegen` / the
-  runtime gain no `data-server`/finance knowledge and no
-  dependency on either; the only place AILang and `data-server`
-  meet is a separate host-side adapter crate (`ail-embed`, M5)
-  that depends on both while neither depends on it. The `audit`
-  architect review verifies this each close.
-  (2) *Single-threaded per computation* — all concurrency is
-  structural and owned by the host; no AILang value ever crosses
-  a thread boundary, so non-atomic RC and "no shared mutable
-  refs" stay intact.
-  (3) *Native-AOT only* — no interpreter/playground is introduced
-  (the "emit LLVM → clang -O2" performance pillar is load-bearing
-  for the swarm).
-
-  **M1 scope.** CLI emit-mode producing a relocatable archive
-  instead of linking an executable; codegen exports an
-  author-designated `fn` under a stable C symbol with a
-  C-compatible signature instead of wrapping `main` (today
-  hard-coded `define i32 @main() { call i8 @ail_<mod>_main() }`,
-  `crates/ailang-codegen/src/lib.rs:556`); a minimal explicit
-  lifecycle so the runtime is usable with no `main`-time setup.
-  Scalar signatures only (`(Int)->Int`, `(Float,Float)->Float`)
-  — no ADT crosses the boundary yet. Coherent stop: AILang
-  arithmetic callable from C/Rust, proven by a host harness that
-  links the `.a`, calls the symbol, asserts the return.
-  - context: 2026-05-18 chat (`data-server` analysis →
-    embedding-ABI decomposition). Spec landed + user-approved
-    2026-05-18: `docs/specs/2026-05-18-embedding-abi-m1.md`
-    (grounding-check PASS on 3rd dispatch; 7 design decisions
-    pinned — additive `FnDef.export: Option<String>` /
-    `(export "<sym>")` mangling-decoupled symbol / `lib<entry>.a`
-    + separate `libailang_rt.a` / no runtime lifecycle API /
-    `--emit=staticlib` suppresses `@main`+`MissingEntryMain` /
-    scalar+effect-free export gate / Task 1 fixed =
-    `MissingEntryMain` build-path baseline pin). Plan landed
-    2026-05-18 `docs/plans/embedding-abi-m1.1.md` (7 tasks; recon
-    file-map Boss-verified against source; both compile-break
-    tasks — `FnDef.export` ~95-site thread, `lower_workspace_inner`
-    `Target` param — scrubbed for self-review-item-7 ordering).
-    Next: `implement`.
+- [ ] **\[feature\]** `ail emit-ir --emit=staticlib` — restore the
+  Decision-5 IR-readability affordance for kernels (M1 fieldtest
+  spec_gap). DESIGN.md Decision 5 makes "the compiler emits LLVM IR
+  as text so the LLM can read what it generated" a load-bearing
+  author affordance, but `ail emit-ir` has no `--emit=staticlib`
+  (only `ail build` does), and `emit-ir` on a `main`-free kernel
+  hits the executable-path `MissingEntryMain` rejection — so the
+  author cannot read the generated `@<sym>` forwarder for an
+  exported kernel, the exact thing M1 introduced. Resolution chosen
+  on the merits: **add** `--emit=staticlib` to `ail emit-ir`
+  (symmetric with `ail build`, reusing the `Target::StaticLib`
+  path) — NOT narrow DESIGN.md (narrowing a load-bearing affordance
+  to dodge a gap is the wrong direction). Scoped feature, no design
+  fork. P1.
+  - context: `docs/specs/2026-05-18-fieldtest-embedding-abi-m1.md`
+    finding [spec_gap]#2.
 
 - [ ] **\[milestone\]** Embedding ABI — M2: per-thread runtime
   context + concurrency safety. `ailang_ctx_new()/_free` threaded