Option G design study + prototype: spec-carried boundary codecs on a flat proxy (#86)

CLAUDE.md

@@ -214,6 +214,7 @@ locally and fail in CI.
 | [dol_issue16_design.md](misc/docs/dol_issue16_design.md) | Issue #16 design: optional key-path write-through / autovivification — opt-in `create_missing`, contextual per-level factory, the `path_set_writeback` boundary engine + persistent-store write-back protocol, scoped plan. Design-only (no code yet). |
 | [dol_issue18_design.md](misc/docs/dol_issue18_design.md) | Issue #18 design: `self`-not-wrapped delegation trap — `wrapped_self` (shipped) now, is-a wrapping (deferred, major) later. |
 | [dol_issue83_design.md](misc/docs/dol_issue83_design.md) | Issue #83 design study: the **inverse** of #18 — a delegated method *receives* the unmapped key. Two delegation routes (a fix for one is a no-op on the other), a 13-package census (mostly **latent**; 12 claims refuted), and options A–F with verified costs: `wrapped_self` has its own silent hole (degrades with no live strong reference), chain-walking free functions break on non-`Store` layers, and the only form correct *by construction* is routing the capability through `__getitem__` as a sibling store. **§5 is the carry-forward list for a future redesign.** |
+| [dol_issue86_design.md](misc/docs/dol_issue86_design.md) | Discussion #86 design study: **Option G** — spec-carried boundary codecs on a flat proxy (wrapt lessons, KT/VT-annotated interface specs, flatten-and-compile codec stacks). Prototype in `dol/_interface_wrap.py` (private, experimental). Headline: is-a does **not** fix #83 for backend-direct method bodies — F and G serve disjoint populations; codec laws (§2.5) are the boundary invariant's fine print; flat-model guarantees are scoped to pure-codec stacks (filters/caches still nest). Open question 0: who owns the wrap_kvs endgame. |
 | [dol_issue10_design.md](misc/docs/dol_issue10_design.md) | Issues #10 + #2 (paired) design: recursive wrapping of nested stores (`recursive_wrap`) + a flat `KvReader`/`KvPersister` view (`flat_store`), sharing one `(path,key,value)` descent frontier and reusing the #16 `path_set_writeback` engine. Load-bearing fix: the recursion read-surface and the write-back boundary must be **different** objects (naive `boundary=self` infinite-loops). Model-2 read + write-into-existing in scope; persistent creation deferred to P3. Design-only (no code yet). |
 | [frontend_dol_ideas.md](misc/docs/frontend_dol_ideas.md) | `zoddal` design: TypeScript KV interface, adapters, Zod bridge, zod-collection-ui integration |