JOURNAL: Boehm stays — orchestrator's call

User's stance on the retirement question raised in 18f / 18g.2:
keep the dual-allocator setup. Boehm = default, RC = validated
alternative ready to flip. Re-opening trigger is operational
(maintenance cost), not performance.

Concrete consequences recorded: no default flip, -lgc stays, and
Decision 9's 'transitional' framing should be re-cast as 'dual
allocator' in a follow-up DESIGN.md edit (queued). Decision 10
holds as the canonical real-time path. The three RC-side debts
from the 18g tidy remain queued and don't block the dual stance.

docs/JOURNAL.md

@@ -8240,3 +8240,42 @@ entry the family is formally closed; the next iter is the
 orchestrator's call between Boehm-retirement Path A and
 Path B (see 18g.2 entry for the framing). Three known debts
 travel forward as queue-items, not as 18-arc loose ends.
+
+## 2026-05-08 — Decision: Boehm stays for now
+
+Orchestrator's call on the retirement question raised in the
+18f / 18g.2 entries: **Boehm is NOT retired.** Both paths
+remain alive on paper, but the operational stance is "keep
+the dual-allocator setup — `--alloc=gc` (Boehm) stays default,
+`--alloc=rc` is the validated alternative". The trigger for
+re-opening the question is operational: if maintaining the
+Boehm path costs significant attention (libgc upgrade pain,
+runtime divergence, build complexity), the case for retirement
+becomes the active queue item. Until then the asymmetry
+(Boehm = default, RC = ready-to-flip) is the right one.
+
+Concrete consequences:
+
+- **No default flip.** `bench/run.sh`, `crates/ail/src/main.rs`'s
+  `--alloc` default, README guidance — all unchanged.
+- **`-lgc` stays as a build dependency** for the gc path. The
+  optional-link footwork that retirement would require stays
+  un-attempted.
+- **Decision 9 (Boehm transitional) is no longer "transitional"
+  in the original sense.** The Decision was framed in 2026-05-07
+  as "transitional until RC is proven"; RC is now proven, but
+  the user's stance is to keep the Boehm path live. A
+  follow-up DESIGN.md edit should re-frame Decision 9 as "dual
+  allocator: Boehm GC for default workloads, RC for real-time-
+  sensitive workloads", removing the "transitional" framing
+  without touching the rest. Recorded as a tidy item; not
+  shipping in this entry.
+- **Decision 10 (RC + uniqueness) holds as the canonical real-
+  time path.** The 18-arc's correctness invariants stand. Any
+  future RC iter is justified by the RC story itself, not by
+  retirement progress.
+
+The three known debts from the 18g tidy (tag-conditional
+partial-drop, let-alias-aware mode propagation, bench-number
+stat-of-N) remain queued. They are RC-side improvements; none
+of them block the dual-allocator stance.