docs: ARCH-BINDINGS.md polish (WS-6)

End-to-end consistency review of the document. One polish edit
landed:

- §1 Scope listed "Person, Artist, Company, User" as binding-target
  entities. Sessie 3a.5 removed `artist` from the registry entirely
  (BACKLOG ARTIST-ADV-BINDING-MODEL); §1 now states "Person,
  Company, User" with a forward-pointer to the appendix that
  documents the v1 omission rationale.

Otherwise no polish needed:
- No stale renamed symbols in code examples (the two
  `dietary_preferences` mentions remaining are deliberate appendix
  content explaining the JSON-path BACKLOG deferral).
- No TODOs / FIXMEs.
- Cross-references to RFC §X / Q-ids are consistent.
- Terminology distinguishes registry (BindingTypeRegistry config +
  lookup), applicator (FormBindingApplicator runtime), and pipeline
  (the broader subject-resolve → conflict-resolve → apply flow)
  appropriately.

Version bumped to v0.6.

Refs: WS-6 sessie 3b Task 6

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

dev-docs/ARCH-BINDINGS.md

@@ -5,6 +5,7 @@
 - v0.1 (skeleton) — 2026-04-25
 - v0.4 — 2026-04-28 — § 8.2 IDOR class tests (sessie 3a backend hardening)
 - v0.5 — 2026-04-28 — Appendix on v1 registry scope (sessie 3a.5 model alignment)
+- v0.6 — 2026-04-28 — §1 polish: align with v1 registry scope (sessie 3b polish review)
 - Owner: Bert
 - Authoritative for the binding pipeline architecture, complementing
   ARCH-FORM-BUILDER.md §17 and §31.
@@ -13,8 +14,10 @@
 ## 1. Scope
 
 The binding pipeline turns a submitted form (`form_submissions`) into
-durable writes against domain entities — Person, Artist, Company, User
-— via per-field bindings configured in `form_field_bindings` (WS-5a).
+durable writes against domain entities — Person, Company, User — via
+per-field bindings configured in `form_field_bindings` (WS-5a). The
+`artist` entity is intentionally absent from the v1 binding-target
+registry; see the appendix for the rationale.
 
 This document describes the end-to-end flow from
 `FormSubmissionSubmitted` event to the post-pipeline state where the