iter embedding-abi-m3.1 (PARTIAL 5/7 + Boss spec-defect repair): single-ctor scalar record crosses the C ABI, ownership follows declared mode

Tasks 1-5 GREEN. T1 baseline pins (re-point annotation + @ailang_rc_alloc
heap-box byte-pin: size=8+n*8, tag@0, fields@8/16). T2 export gate widened
(is_c_scalar -> two-level is_c_abi_type: single-ctor all-Int/Float record;
multi-ctor/Str/List/nested still RED; gate suite 10/10; M1 adt-ret must-fail
re-pointed to multi-ctor+Str Reading). T3 codegen forwarder widened
(llvm_scalar record Type::Con -> ptr; M2 forwarder body byte-unchanged;
3/3 staticlib pins). T4/T5 E2E record round-trip own+borrow, global
leak-freedom.

Boss spec-consistency repair (M2.1-precedent class): orchestrator
correctly BLOCKED Task 5 on a genuine spec defect -- the single-ctx-readback
allocs==frees proof model is unsatisfiable for borrow (and only
coincidentally passes for own) because M2's TLS-ctx is bound only during
the synchronous forwarder call, so host-side decs land on g_rc_*, not ctx.
Boss-verified globally leak-free + value-correct both modes. Spec + plan +
harness amended to the stronger global model (sum all ailang_rc_stats:
lines; the M2-TLS cross-attribution documented as correct behaviour). No
fresh grounding-check (removes an over-strong measurement assumption).

Tasks 6 (DESIGN.md frozen-layout SSOT + lockstep pointers + freeze wording
+ enforceability demo) and 7 (workspace-green gate) re-dispatched on the
amended plan. Bench/architect milestone-close is audit-owned.

iter embedding-abi-m3.1 (PARTIAL); INDEX.md line deferred to the DONE commit

examples/embed_backtest_step_record.ail

@@ -0,0 +1,16 @@
+(module embed_backtest_step_record
+
+  (data State
+    (ctor State (con Float) (con Int)))
+
+  (fn step
+    (export "backtest_step")
+    (type
+      (fn-type
+        (params (own (con State)) (con Float))
+        (ret (con State))))
+    (params st sample)
+    (body
+      (match st
+        (case (pat-ctor State acc n)
+          (term-ctor State State (app + acc sample) (app + n 1)))))))

examples/embed_backtest_step_record_borrow.ail

@@ -0,0 +1,16 @@
+(module embed_backtest_step_record_borrow
+
+  (data State
+    (ctor State (con Float) (con Int)))
+
+  (fn step
+    (export "backtest_step")
+    (type
+      (fn-type
+        (params (borrow (con State)) (con Float))
+        (ret (con State))))
+    (params st sample)
+    (body
+      (match st
+        (case (pat-ctor State acc n)
+          (term-ctor State State (app + acc sample) (app + n 1)))))))

examples/embed_export_adt_ret_rejected.ail

@@ -1,11 +1,12 @@
 (module embed_export_adt_ret_rejected
-  (data Pair
-    (ctor Pair (con Int) (con Int)))
+  (data Reading
+    (ctor Missing)
+    (ctor Sample (con Int) (con Str)))
   (fn f
     (export "f")
     (type
       (fn-type
         (params (con Int))
-        (ret (con Pair))))
+        (ret (con Reading))))
     (params n)
-    (body (app Pair n n))))
+    (body (term-ctor Reading Sample n "tick"))))

examples/embed_export_list_field_record_rejected.ail

@@ -0,0 +1,11 @@
+(module embed_export_list_field_record_rejected
+  (data List
+    (ctor Nil)
+    (ctor Cons (con Int) (con List)))
+  (data Boxed
+    (ctor Boxed (con Int) (con List)))
+  (fn f
+    (export "f")
+    (type (fn-type (params (con Int)) (ret (con Boxed))))
+    (params n)
+    (body (term-ctor Boxed Boxed n (term-ctor List Nil)))))

examples/embed_export_multictor_rejected.ail

@@ -0,0 +1,9 @@
+(module embed_export_multictor_rejected
+  (data Either2
+    (ctor L (con Int))
+    (ctor R (con Float)))
+  (fn f
+    (export "f")
+    (type (fn-type (params (con Int)) (ret (con Either2))))
+    (params n)
+    (body (term-ctor Either2 L n))))

examples/embed_export_record_ok.ail

@@ -0,0 +1,14 @@
+(module embed_export_record_ok
+  (data State
+    (ctor State (con Float) (con Int)))
+  (fn step
+    (export "step")
+    (type
+      (fn-type
+        (params (own (con State)) (con Float))
+        (ret (con State))))
+    (params st sample)
+    (body
+      (match st
+        (case (pat-ctor State acc n)
+          (term-ctor State State (app + acc sample) (app + n 1)))))))

examples/embed_export_str_field_record_rejected.ail

@@ -0,0 +1,8 @@
+(module embed_export_str_field_record_rejected
+  (data Tagged
+    (ctor Tagged (con Int) (con Str)))
+  (fn f
+    (export "f")
+    (type (fn-type (params (con Int)) (ret (con Tagged))))
+    (params n)
+    (body (term-ctor Tagged Tagged n "x"))))

examples/embed_record_layout_carrier.ail

@@ -0,0 +1,30 @@
+(module embed_record_layout_carrier
+
+  (data Pt
+    (ctor Pt (con Int) (con Int)))
+
+  (fn mk
+    (type
+      (fn-type
+        (params (con Int) (con Int))
+        (ret (con Pt))))
+    (params a b)
+    (body (term-ctor Pt Pt a b)))
+
+  (fn sum_pt
+    (type
+      (fn-type
+        (params (own (con Pt)))
+        (ret (con Int))))
+    (params p)
+    (body
+      (match p
+        (case (pat-ctor Pt x y)
+          (app + x y)))))
+
+  (fn main
+    (type (fn-type (params) (ret (con Unit)) (effects IO)))
+    (params)
+    (body
+      (let s (app int_to_str (app sum_pt (app mk 3 4)))
+        (do io/print_str s)))))