chore(.machine_readable): convert 6a2 checkpoint files from Scheme to A2ML

Convert all .machine_readable/6a2/ files from Guile Scheme format to
A2ML (a2ml) format. Preserves all data (project name, version, milestones,
blockers, actions) in the A2ML TOML-like structure.

Also fills in unfilled template placeholders ({{CURRENT_YEAR}}, {{AUTHOR}},
etc.) with concrete values.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: hyperpolymath

.machine_readable/6a2/AGENTIC.a2ml

@@ -1,12 +1,12 @@
 # SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # AGENTIC.a2ml — AI agent constraints and capabilities
 # Defines what AI agents can and cannot do in this repository.
 
 [metadata]
 version = "0.1.0"
-last-updated = "{{CURRENT_DATE}}"
+last-updated = "2026-04-11"
 
 [agent-permissions]
 can-edit-source = true

.machine_readable/6a2/ECOSYSTEM.a2ml

@@ -1,17 +1,17 @@
 # SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # ECOSYSTEM.a2ml — Project ecosystem position
 # Relationships, dependencies, integration points.
 
 [metadata]
 version = "0.1.0"
-last-updated = "{{CURRENT_DATE}}"
+last-updated = "2026-04-11"
 
 [project]
-name = "{{PROJECT_NAME}}"
-purpose = "{{PROJECT_PURPOSE}}"
-role = "{{PROJECT_ROLE}}"  # e.g. ffi-infrastructure, cli-tool, library, service
+name = "vscode-a2ml"
+purpose = ""  # TODO: describe project purpose
+role = ""  # TODO: describe project role  # e.g. ffi-infrastructure, cli-tool, library, service
 
 [position-in-ecosystem]
 tier = "infrastructure"  # 1 | 2 | infrastructure

.machine_readable/6a2/META.a2ml

@@ -1,18 +1,18 @@
 # SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # META.a2ml — Project meta-level information
 # Architecture decisions, design rationale, governance.
 
 [metadata]
 version = "0.1.0"
-last-updated = "{{CURRENT_DATE}}"
+last-updated = "2026-04-11"
 
 [project-info]
-type = "{{PROJECT_TYPE}}"  # library | binary | monorepo | service | website
+type = "library"  # TODO: update type (library|binary|service|website|monorepo)  # library | binary | monorepo | service | website
 languages = []             # e.g. ["rust", "zig", "idris2"]
 license = "PMPL-1.0-or-later"
-author = "{{AUTHOR}} ({{OWNER}})"
+author = "Jonathan D.A. Jewell (hyperpolymath)"
 
 [architecture-decisions]
 # ADR format: status = proposed | accepted | deprecated | superseded | rejected

.machine_readable/6a2/NEUROSYM.a2ml

@@ -1,12 +1,12 @@
 # SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # NEUROSYM.a2ml — Neurosymbolic integration metadata
 # Configuration for Hypatia scanning and symbolic reasoning.
 
 [metadata]
 version = "0.1.0"
-last-updated = "{{CURRENT_DATE}}"
+last-updated = "2026-04-11"
 
 [hypatia-config]
 scan-enabled = true

.machine_readable/6a2/PLAYBOOK.a2ml

@@ -1,12 +1,12 @@
 # SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # PLAYBOOK.a2ml — Operational playbook
 # Runbooks, incident response, deployment procedures.
 
 [metadata]
 version = "0.1.0"
-last-updated = "{{CURRENT_DATE}}"
+last-updated = "2026-04-11"
 
 [deployment]
 # method = "gitops"  # gitops | manual | ci-triggered

.machine_readable/6a2/STATE.a2ml

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: PMPL-1.0-or-later
-# Copyright (c) {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # STATE.a2ml — Project state checkpoint (META-TEMPLATE)
 #