chore(v→zig): delete V-lang API shim, redirect docs to Zig FFI (#78)

Per estate-wide owner directive (2026-05-28): Zig is the default for
APIs/FFIs; Idris2 owns ABIs. Deletes api/v/stapeln.v (thin V wrapper
around the existing ffi/zig/). Doc sweep: api/README.adoc rewritten to
describe the Zig FFI as the canonical adapter; stapeln.toml comment
updated from api/v/ to ffi/zig/.

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

Author: hyperpolymath

api/README.adoc

@@ -2,22 +2,24 @@
 = api/
 API contract definitions and interface specifications for stapeln.
 
-Contains V-language interface descriptions (`.v`) used to define the external API
-surface before implementation. These serve as machine-readable interface contracts
+Contains Zig API interface descriptions used to define the external API surface
+before implementation. These serve as machine-readable interface contracts
 independent of any single backend implementation.
 
 == Contents
 
-* `v/stapeln.v` — V-language API surface definition for the stapeln backend.
+* `zig/` — Zig API surface for the stapeln backend (see `ffi/zig/`).
 
 == Relationship to Backend
 
 The `api/` tree defines *what* the API does; `backend/` contains the Elixir/Phoenix
-implementation of *how* it does it. Changes to `api/stapeln.v` should be reflected
-in the corresponding Phoenix controllers and GraphQL schema (`backend/schema.graphql`).
+implementation of *how* it does it. Changes to the Zig API surface should be
+reflected in the corresponding Phoenix controllers and GraphQL schema
+(`backend/schema.graphql`).
 
-== Note on V-lang
+== Language Policy
 
-V-lang files here are interface definitions retained for documentation purposes.
-Per estate policy (2026-04-10), new V-lang code is not introduced; migration to
-Zig/Rust interface tooling is planned. See the root `ROADMAP.adoc`.
+Per estate policy (2026-05-28), Zig is the default language for all APIs and
+FFIs across the estate; Idris2 owns ABI contracts. The legacy V-language
+interface file (`api/v/stapeln.v`) was removed in the V-lang remediation pass
+— the live Zig FFI at `ffi/zig/` is the canonical adapter.

api/v/stapeln.v

@@ -18,7 +18,7 @@
 #   container-stack/rokur/    — Deno secrets management gate
 #   dom-mounter/ — ReScript DOM mounting library
 #   ephapax-modules/ — Ephapax linear type modules
-#   api/v/       — V-lang API bindings
+#   ffi/zig/     — Zig FFI (canonical API surface; Idris2 owns ABI)
 
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