Claude/affinescript error lang proofs r mh9s (#36)

* docs+test: frame Echo as visible decomposition across three planes

Make Error-Lang's dissembling/decompositional narrative explicit and ensure
both human and bot documentation recognise it: Echo is structured loss made
VISIBLE, governed by the invariant "decomposition must be visible"
(echo_to_residue is never a silent cast, EchoR is never an Echo with a missing
field, the stability debit is never hidden).

Documentation:
- docs/Echo-Decomposition.adoc (new): the authoritative narrative — the three
  decomposition planes (syntactic, semantic/runtime, type-checking), the
  visibility invariant, the full contract, and the echo-types/EchoTypes.jl
  lineage.
- docs/Design-Philosophy.adoc: new "Structured Loss" section tying Echo into
  consequence amplification + the stability score.
- README.adoc: front-door paragraph on the decompositional framing + Echo.
- spec/type-system.md §7.5: decomposition obligations + visibility invariant.
- Bot-facing: 0-AI-MANIFEST.a2ml (core narrative, critical invariant, taxonomy
  pointers), META.a2ml (ADR-0001), NEUROSYM.a2ml (symbolic rules for the
  erasure cost, no-coercion, and echo_input-not-on-residue invariants).

Proof/test pass across the three planes:
- EchoRuntimeTest.res (new, semantic/runtime): echo builds VEcho; echo_input
  works on VEcho and fails on a residue; echo_output works on both;
  echo_to_residue yields VResidue; the witness is genuinely gone; stability is
  debited exactly once by erasure and never by projection.
- TypeCheckerTest.res: EchoR does not unify back into Echo; no implicit
  Echo->B coercion; echo_output on a residue yields the retained output.
- ParserTest.res: nested Echo<Echo<...>> (>> splitting); malformed Echo raises
  a diagnostic.

* docs: weave visible-decomposition narrative into spec, curriculum, examples, manifests

Second pass after the survey — extend the Echo "decomposition must be visible"
narrative consistently across the remaining human and bot documentation, and
add a runnable example. Kept strictly Error-Lang-specific.

Human docs:
- docs/Error-Lang.adoc: new "Structured Loss Is Visible (Echo)" design
  principle beside Jenga Semantics; Echo/EchoR keywords; Echo statement +
  annotation syntax.
- docs/Curriculum.adoc: new "Lesson 11: Structured Loss (Echo)".
- docs/Educational-Framework.adoc: Echo decomposition bullet in Week 5-6.
- docs/Error-Categories.adoc: Echo-erasure stability debit under Stability
  Score Impact (noted as a deliberate cost, not an error category).

Example:
- examples/11-echo-decomposition.err: runnable demo — echo, projection,
  echo_to_residue with a visible stability drop, residue_strictly_loses, and
  echo_input-on-residue rejected in a gutter zone.

Bot manifests:
- ECOSYSTEM.a2ml: fill purpose/role/category; record the Echo lineage
  (echo-types, EchoTypes.jl) under related-projects.
- AGENTIC.a2ml: agent constraint preserving visible decomposition.

* docs: complete documentation — EXPLAINME, contractiles, manifests

- EXPLAINME.adoc: comprehensive human/agent orientation document covering
  all core concepts (Echo types, paradoxes, stability score, gutter zone),
  architecture, file map, and next steps

- contractiles/: fully populated with Error-Lang-specific content
  * must/Mustfile: 11 invariant checks (SPDX headers, Echo decomposition
    visibility, grammar canonicity, banned languages, AI manifest presence)
  * dust/Dustfile: 7 recovery handlers including echo-invariant-violation,
    stability-debit-missing, residue-unified-with-echo, ci-governance-failure
    (documents the pre-existing ReScript ban clearly)
  * trust/Trustfile.hs: trust model and 7 verification steps
  * lust/Intentfile: 5 intent items (INTENT-001 AffineScript re-target through
    INTENT-005 LSP Echo decomposition tracking)

- .machine_readable/6a2/STATE.a2ml: updated to v0.5.0 with full session
  history, CI status, known pre-existing failure documented

- 0-AI-MANIFEST.a2ml: fixed all path references (.scm → 6a2/*.a2ml),
  added EXPLAINME, contractiles, and compiler file locations; added known
  pre-existing CI failure section; added session exit sequence

https://claude.ai/code/session_012vdXtQduudBNugv3ZPtQik

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Co-authored-by: Claude <noreply@anthropic.com>

Author: hyperpolymath