docs: record the DocIr-composition seam (a2ui = DocRenderer's fourth adapter)

[AdaWorldAPI]

What

Aligns a2ui-rs awareness (CLAUDE.md) with the OGAR DocIr composition grounding (OGAR #217 / #218). Docs-only, no code.

The composition ruling generalizes this arc, it does not compete with it — render_stream.rs already says "one template projection; serve it as a living screen or re-issue it as a document." This records the OGAR-side widenings this repo will absorb as rename-follows, not re-derivations:

• a2ui is DocRenderer's fourth adapter (screen == document, A3) — no parallel renderer trait; when OGAR renames ProjectionRenderer → DocRenderer, this repo consumes that trait.
• The FieldView we consume is a fold being widened. render_field_view's FieldView struct is the Text-leaf reading of the E-ONE-MASK-THREE-PORTS fieldview fold; when OGAR widens it to the renderer-neutral enum FieldView (struct → FieldRow), the wasm/server/paint tiers consume the enum's fold — the paint tier's hand-rolled Skin{Form,Flow} widget dispatch becomes the variant match. T1 holds (skins, not a second doc-IR vocabulary).
• ObjectSlot = the resolve_nested L1/L2 addressing made explicit (desktop → window → region → widget = the A3 Klickwege brick + ObjectRef + ResolutionMode); behavior still by address (T2).

No code change — the composition types are OGAR-side named gaps. This is the seam record so the widening lands as a rename-follow.

Test plan

Docs-only; no code paths touched. No model identifier in the artifact.

Generated with Claude Code

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Generated by Claude Code

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