docs(defork-audit): record #6341 execution reality — Root B narrowed to shadow-removal; 3 walls re-map follow-ons

docs/plans/dag-v2-defork-audit.md

@@ -152,6 +152,16 @@ The operator ruled the FreeMonoid/algebra single authority that category (b) was
 - **The emit-seam (Root A) is jolly-cat's** — this lane does not touch `05_emit_rust.dag`.
 - **Stage every file of a rename/collapse together** (the auto-committer atomicity hazard, §3 above).
 
+### Execution update (#6341, 2026-07-07) — Root B narrowed to shadow-removal; three walls re-map the follow-ons
+
+`#6341` landed the **core of Root B**: the `FreeMonoid`/`Empty`/`Cons` variant-drop shadow is removed — the coproduct now lives once in `dag/std/algebra.dag:111`, `v2.std.algebra` imports it, 158 importers repointed. But implementing the *fuller* Root B (move the ops; unify the definition; promote QualifiedName) surfaced **three walls by-execution** that re-scope the remaining lanes. Full trace + census: **[algebra-grounding-unification-design.md §9](algebra-grounding-unification-design.md)**. Summary for the roadmap:
+
+- **A — reserved-name → builtin dissolution.** `dag/std/algebra.dag`'s templates *declare* the builtin collection-method names (`fold`/`map`/`filter`/`length`/`any`/`contains`/`skip`/…); a `std.*` free fn matching one breaks the whole method table (bare `fold(...)` fails corpus-wide). So the 8 ops `filter`/`length`/`any`/`contains`/`skip`/`is_empty` (+ `non_empty`/`bag_eq`) **cannot** move to `std.*` — they are free-fn duplicates of dag builtins and must *dissolve into* `.filter()`/`.length()` at v2 call sites (a lane, not a rename — a `list_filter` nickname is a §3 violation).
+- **B — Root A is UNOWNED and confirmed load-bearing for the ops.** `src/v1/05_emit_rust.dag` hardcodes `crate::v2_std_algebra::{freemonoid_empty,fold_list,list_snoc_item}` for the `String=FreeMonoid<Char>` host bridge — so those 3 ops can't move until Root A relocates them. **jolly-cat (the assigned Root-A owner above) is no longer in the tree** (operator, 2026-07-06); the `String`/`List` alias grounding (§3b.2 above) is blocked until Root A is re-dispatched.
+- **C — QualifiedName is `node`-gated, not algebra-gated.** `src/v2/std/qualified_name.dag` imports `v2.std.node`/`v2.std.diagnostic`/`v2.std.compilers.lexing`, all v2-only (`dag→v2` denied). FreeMonoid single-authority was **necessary but not sufficient**; promoting QualifiedName to `std.qualified_name` (unparking `type-env-single-authority-design.md` §5.1) needs the deferred **`node` defork** too (category (c), v1-delete).
+
+Definition-unification (§3b.2: delete the dag record-of-methods *definition*) and the structure-record grounding (12 of 14 records diverge) remain deferred; the `flag-ANY` co-occurrence wall for the full `algebra` pair greens only after those. `#6341` removed the *dangerous* variant-drop shadow — the record shadow left is the benign record-with-record kind.
+
 ## Dissolution trigger (DESIGN §6)
 
 Delete this doc when the fork census reaches zero — when no `std` basename denotes two concepts and every concept has a single authority. The census now has **three categories**, dissolving on different triggers: **(a) True mirrors** (`reducible`, `measure`) — mechanical collapse; dissolve into their carriers (absent files, re-pointed imports) as each PR lands. Plus `probe_selector` (the step-4 data-import unblock), independent. **(b) Grounding divergences** (`algebra`, `logic`, `nat`, `integer`, `float`, `effects`, `verification`) — downstream of the operator's grounding-unification design; tracked here as decision-input until that design lands and the repoints become mechanical. **(c) v1-artifact collisions** (`node`, `coercion`) — deferred to v1-shrink; trigger "when v1's consumers of `dag/std/{node,coercion}` are removed" (`node` self-dissolves, `coercion` shrinks to a v1-free rename). At the point all three are resolved the carriers tell the whole story and this audit is redundant.