refactor(descriptiles): migrate .machine_readable/6a2 -> descriptiles (estate naming canon)

Estate naming mandate (2026-06-30): the machine-readable metadata family is
`descriptiles`; `6a2` is fully deprecated and must never be reintroduced.
`rsr-template-repo` already led this rename (PR #128). This brings AffineScript
into line.

Changes (mechanical, word-boundaried `\b6a2\b` -> `descriptiles`, so checksum
substrings are untouched; Cargo.lock hash coincidences excluded):
- `git mv .machine_readable/6a2 .machine_readable/descriptiles` (6 .a2ml files)
- updated the one code dependency: tools/check-doc-truthing.sh STATE_FILE path
- updated .machine_readable/TRUST.contractile deny-rule path
- updated ~30 doc/metadata references (paths + "6a2 metadata" family-name prose)

Verified (dune 3.24.0, system OCaml 4.14.1 + opam switch as-verify):
- `dune build` = exit 0 (no build impact)
- zero `\b6a2\b` references remain (excl. Cargo.lock checksums)
- check-doc-truthing.sh reads the renamed STATE path correctly
Two doc gates (README->SOUNDNESS.adoc, README->CAPABILITY-MATRIX.adoc) are
RED on main independently of this change (README untouched here); tracked
separately.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.machine_readable/descriptiles/AGENTIC.a2ml

@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: MPL-2.0
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# AGENTIC.a2ml — AI agent constraints and capabilities
+[metadata]
+version = "0.1.0"
+last-updated = "2026-04-11"
+
+[agent-permissions]
+can-edit-source = true
+can-edit-tests = true
+can-edit-docs = true
+can-edit-config = true
+can-create-files = true
+
+[agent-constraints]
+# What AI agents must NOT do:
+# - Never use banned language patterns (believe_me, unsafeCoerce, etc.)
+# - Never commit secrets or credentials
+# - Never use banned languages (TypeScript, Python, Go, etc.)
+# - Never place state files in repository root (must be in .machine_readable/)
+# - Never use AGPL license (use MPL-2.0)
+
+[maintenance-integrity]
+fail-closed = true
+require-evidence-per-step = true
+allow-silent-skip = false
+require-rerun-after-fix = true
+release-claim-requires-hard-pass = true
+
+[automation-hooks]
+# on-enter: Read 0-AI-MANIFEST.a2ml, then STATE.a2ml
+# on-exit: Update STATE.a2ml with session outcomes
+# on-commit: Run just validate-rsr
+
+# ── Disambiguation ────────────────────────────────────────────────────────
+# AI agents have repeatedly conflated this repo (AffineScript) with the
+# unrelated language Ephapax (hyperpolymath/ephapax). The two share exactly
+# one thing — both target hyperpolymath/typed-wasm — and otherwise have
+# different ASTs, type checkers, compilers, and proof stories. The shared
+# `affine` syllable names a substructural-logic property in BOTH cases
+# (it's a logic-family name), not a project relationship. Ephapax is itself
+# dyadic and contains an `ephapax-affine` *sublanguage* — that sublanguage
+# is NOT AffineScript.
+[disambiguation]
+this = "hyperpolymath/affinescript"
+canonical-name = "AffineScript"
+distinct-from = ["hyperpolymath/ephapax"]
+shared-with-distinct = ["hyperpolymath/typed-wasm"]
+ephapax-affine-sublanguage-is-not-affinescript = true
+canonical-doc = "https://github.com/hyperpolymath/nextgen-languages/blob/main/docs/disambiguation/ephapax-vs-affinescript.md"
+canonical-memory-entry = "feedback_affinescript_ephapax_siblings_not_impl_proof.md"
+do-not-apply-cross-repo-lessons-without-explicit-check = true

.machine_readable/descriptiles/ECOSYSTEM.a2ml

@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: MPL-2.0
+# ECOSYSTEM.a2ml — Ecosystem position
+# Converted from ECOSYSTEM.scm on 2026-03-21
+
+[metadata]
+project = "affinescript"
+ecosystem = "hyperpolymath"
+
+[position]
+type = "programming-language"
+purpose = "A systems programming language combining affine types, dependent types, row polymorphism, and extensible effects, compiling to WebAssembly"
+
+[pipeline]
+position = "co-product"
+chain = "katagoria → typell → typed-wasm → PanLL"
+notes = "AffineScript compiles to typed WasmGC. TypeLL grounds its type system. typed-wasm provides the shared binary layout and ABI conventions."
+coordination = "nextgen-typing"
+
+[related-projects]
+projects = [
+  { name = "typell", relationship = "type-theory-foundation", notes = "TypeLL's open-ended progressive framework grounds AffineScript's type system. typell-affinescript bridge crate." },
+  { name = "typed-wasm", relationship = "aggregate-library", notes = "Shared binary layout conventions for WasmGC cross-language calls. AffineScript Option[T]/Result[T,E]/String have agreed layouts here." },
+  { name = "nextgen-typing", relationship = "coordination-parent", notes = "Coordination monorepo for the type theory pipeline. Canonical architecture doc." },
+  { name = "ephapax", relationship = "sibling-wasm-target", notes = "Both compile to typed WasmGC. Independent designs; converge at binary level via typed-wasm." },
+  { name = "katagoria", relationship = "research-upstream", notes = "Type theory research origination. Future AffineScript type system extensions may originate there." },
+  { name = "panll", relationship = "consumer", notes = "AffineScript is one of PanLL's development language targets." },
+]