docs(proposals): 0001 — add resolved Open Question #6 (access-site carrier)

Surfaces the access-site carrier gap discovered while pre-staging the
L2 codec in PR #77: the typedwasm.regions section says *which regions
exist* but doesn't say which (region_id, field_id) any individual wasm
load/store targets. Sufficient for L2-the-spec; insufficient for
L2-the-enforcement.

Owner-resolved 2026-05-27 (see typed-wasm#78): adopt **option A** —
a per-instruction access-site carrier (typedwasm.access-sites)
mapping (func_idx, instruction_byte_offset) → (region_id, field_id).
Wire-format design lands in docs/proposals/0002-...adoc as a
follow-up; verify_region_binding (omitted from PR #77) is gated on
that proposal's acceptance.

Refs #78 (access-site carrier — option A)
Refs #77 (codec pre-stage that discovered the gap)
Refs #34 (parent issue)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

docs/proposals/0001-multi-producer-carrier-section.adoc

@@ -289,6 +289,24 @@ verification, not debug info, and must not be optimised out.
   cross-module.  Out of scope of v1 (single-module L2–L6 is the v1
   milestone); needs its own proposal.
 
+. **Access-site carrier (RESOLVED — option A).** Discovered during
+  the pre-stage codec in PR #77: this proposal's `typedwasm.regions`
+  section says *which regions exist* but does **not** say which
+  `(region_id, field_id)` any individual wasm load/store targets.
+  The source-level checker sees `region.get $r .f`; post-codegen
+  that's just `i32.load offset=N align=A`, with the `($r, .f)`
+  annotation gone. So this proposal is sufficient for
+  L2-the-spec (schema agreement) but insufficient for
+  L2-the-enforcement (every typed access resolves to a declared
+  region/field). Owner-resolved 2026-05-27 (see typed-wasm#78):
+  **adopt option A — a per-instruction access-site carrier
+  (`typedwasm.access-sites`) mapping
+  `(func_idx, instruction_byte_offset) → (region_id, field_id)`**.
+  Wire-format design for that section lands in a follow-up proposal
+  (`docs/proposals/0002-...adoc`); the L2 verifier pass
+  (`verify_region_binding`, omitted from PR #77) is gated on
+  that proposal's acceptance.
+
 == Acceptance criteria
 
 . Reviewed and signed off by maintainers of `affinescript` and