board: D-BSW-0 requires BOTH feature configurations, as the plan already did

Found by verifying a review claim rather than dismissing it. The codex
connector reported a commit `a0f7759` reconciling this PR's scope; that sha
exists nowhere -- its own report says the environment had no git remote and no
authenticated gh, so the commit never left its sandbox. Checking its five
claims against this branch instead of hunting the sha turned up one that was
NOT satisfied here.

The plan's M0 says both `--features mailbox-thoughtspace` and
`--features with-engine,mailbox-thoughtspace` are the deliverable, because
`dispatch_busdto` and `busdto_bridge_test.rs` are `with-engine`-gated
(`engine_bridge.rs:280`) and a mailbox-only job compiles neither -- it stays
green while the paired configuration breaks. The board's D-BSW-0 row still said
"One line" and named only `mailbox-thoughtspace`, so an implementer working from
the board would add one job and mark the deliverable done, satisfying the row
while leaving the actual gap open.

Exactly the defect shape CodeRabbit caught for D-BSW-2 one commit ago: the fix
landed in the plan and was not propagated to the board, and the two then
disagreed. A per-deliverable plan/board diff is the check that catches this
class; grepping for the fixed phrase does not, because the plan matches and the
board's silence looks like absence of an opinion rather than a contradiction.

Row edit only: 1811 lines before and after, D-BSW 5 rows, D-NXG 12 rows.
Gates re-run: index byte-identical (regenerated after the board write),
append-only OK (9 checked), no new citation decay, dids green, zero crates/.

Author: claude

.claude/board/STATUS_BOARD.md

@@ -15,7 +15,7 @@ records against itself.
 
 | D-id | deliverable | status |
 |---|---|---|
-| D-BSW-0 | Put `mailbox-thoughtspace` under CI — the 4 `w2_differential` bit-identity tests and every `BackingStoreWrite` Mailbox arm currently have ZERO coverage (no workflow builds the feature). One line; precedent `rust-test.yml:158-173`. Falsifier: test count strictly increases and the 4 tests appear by name | Queued (plan `bindspace-mailbox-soa-wiring-v1` §4) |
+| D-BSW-0 | Put the feature under CI in **BOTH** configurations — `--features mailbox-thoughtspace` AND `--features with-engine,mailbox-thoughtspace` (plan §4 M0). One job is NOT the deliverable: `dispatch_busdto` and `busdto_bridge_test.rs` are `with-engine`-gated (`engine_bridge.rs:280`), so a mailbox-only job compiles neither and stays green while the paired configuration breaks. Today the 4 `w2_differential` bit-identity tests and every `BackingStoreWrite` Mailbox arm have ZERO coverage. Precedent `rust-test.yml:158-173`. Falsifier: test count strictly increases in each configuration and the 4 tests appear by name | Queued (plan `bindspace-mailbox-soa-wiring-v1` §4) |
 | D-BSW-1 | Wire `BackingStoreWrite` (`backing.rs:164-314`, 9 methods, both arms real) into the driver write path — it has zero callers outside its own test module. Adds a caller, not a capability | Queued (blocked on D-BSW-0) |
 | D-BSW-2 | Route the production BindSpace writers through the shim — **eight sites, not five**: `engine_bridge` `write_qualia_observed:490` / `write_qualia_17d:548` (direct), `persist_cycle:784` (edge+meta; cycle write is the documented loss), `ingest_codebook_indices:58` (composed last); plus the three `serve.rs` handlers `encode_handler:607` (direct `set_content`), `:139` and `:639` (via `Arc::get_mut`). `dispatch_busdto:281` is **excluded pending a decision** — its `qualia_f32` tenant has no MailboxSoA equivalent (plan §4). All eight must land BEFORE D-BSW-3 or dispatch reads the mailbox while `/v1/shader/encode` writes the singleton | Queued (blocked on D-BSW-1) |
 | D-BSW-3 | Populate `mailboxes` from a production path — today the only `with_mailbox` caller is `tests/w2_differential.rs:277`, so a feature-on build still takes the singleton fallback (`driver.rs:217`) | Queued (blocked on D-BSW-2) |