[ARCHITECTURE] Compose optional precision tools without a mandatory Word conversion

[hyperpolymath]

Goal

Define DocMatrix, Formatrix Docs, and Blocky Writer as independent options that
can compose into one precision-document suite. No user should have to convert
everything to Microsoft Word—or any other mandatory hub format—to obtain
multi-format viewing, editing, conversion, or fixed-layout form placement.

Component boundaries

• DocMatrix: multi-format conversion and precision coordination.
• Formatrix Docs: tabbed views of one logical document across TXT,
  user-selected-delimiter tabular text, Markdown, AsciiDoc, Djot, and A2ML;
  synchronised editing is the intended progression.
• Blocky Writer: fitting and placement into fixed-layout PDF and
  application-form boxes, baselines, and per-character cells designed for hand
  spacing.
• ForthWall: an optional, proposed capability-bounded execution layer for
  critical operations; never a mandatory end-user product or runtime.

Each component must remain useful on its own. Composition is explicit and
user-selected.

Precision composition contract

1. The user's native input remains authoritative unless they explicitly select
   another representation.
2. Every conversion identifies its parser/renderer versions and declares what
   is preserved, approximated, unsupported, or lost.
3. Intermediate representations are inspectable, content-addressed, and linked
   to their source; no opaque Word or proprietary round trip is required.
4. No component silently normalises punctuation, Unicode/whitespace,
   attribution, terminology, document structure, or page geometry.
5. Ambiguous or lossy transformations are proposals requiring approval.
6. A composed operation carries exact input/output hashes, provenance,
   evidence spans or page coordinates, and a replayable operation record.
7. Each component verifies its own contract, then an independent end-to-end
   verifier checks the composed result.
8. Audit/propose is the non-interactive default. Automatic mutation remains
   disabled for ambiguous or critical operations.

Proof obligations do not transfer

• Conversion round-trip tests do not prove synchronised editor state.
• Editor tests do not prove fixed-layout PDF geometry.
• Exact page coordinates do not prove semantic correctness.
• Deterministic Forth execution does not prove that the chosen operation or
  location was correct.

Every cross-component pipeline must satisfy all participating contracts plus
end-to-end fixtures for the actual composition.

Acceptance criteria

• Each repository README and GitHub description states its own boundary and
  links to the other optional components.
• A versioned interchange contract defines content, format identity,
  provenance, hashes, evidence spans, page coordinates, loss reporting, and
  refusal reasons.
• Users can run each component independently and opt into combinations.
• No supported workflow requires Microsoft Word as an intermediate.
• Native-format and lossy-conversion policies are configurable and visible.
• Cross-component positive, negative, ambiguous, stale-input, lossy,
  round-trip, and fault-injection fixtures run in CI.
• The ForthWall safety blocker in [SAFETY BLOCKER] Do not connect ForthWall exact-placement repair to CI #70 remains in force until its separate
  implementation and proof criteria are met.

[hyperpolymath]

Final architecture clarification after reviewing the current Groove, Spline,
and Cleave responsibilities:

• Do not introduce another runtime integration engine for the precision
  tools.
• Each product remains independently complete and owns its capability schemas.
• Groove discovers products, advertises capabilities, negotiates structural
  compatibility, and permits graceful absence.
• Spline eventually carries consumer-owned typed diagnostics, conversion plans,
  geometry, provenance, and verification results; it must not become a new
  universal document serialiser. Spline is currently seed-only, so static typed
  records/direct invocation are the bootstrap path.
• Cleave bounds authority, lifecycle, isolation, teardown, and integration
  posture. Its demonstrated kernel does not yet prove the full multiprocess/wire
  surface.
• Users select profiles and permitted capabilities. Configuration expresses
  intent; it cannot override a failed Groove structural-compatibility check.
• ForthWall begins disconnected/audit/propose/verify-only. A critical profile
  means less authority and more independent evidence, not more aggressive
  automation.

A small catalogue or umbrella page may document tested combinations and
profiles, but it must not duplicate product implementations or become a hidden
mandatory hub. End-to-end conformance fixtures are still required and may live
with the participating product/Groove conformance suites rather than in a new
integration repository.