CI: warm ahash process statics before the capi lifecycle allocator oracle arms

crates/capi/tests/resource_lifecycle.rs

@@ -130,7 +130,23 @@ fn snapshot() -> Snapshot {
     }
 }
 
+/// Initialize the process-lifetime statics that the JSON frontend's dependencies create lazily,
+/// so the first observed window is not charged for them.
+///
+/// `json-syntax` 0.12.5 indexes every object through `hashbrown` 0.12's `DefaultHashBuilder`,
+/// which is `ahash` 0.7's `RandomState`. Its first construction in a process boxes three
+/// `once_cell::race::OnceBox` statics (`RAND_SOURCE`, its inner `Box<dyn RandomSource>`, and the
+/// `SEEDS` array: 8 + 16 + 64 bytes) that live until process exit and belong to no capi owner.
+/// ahash's `build.rs` forces `runtime-rng` on every hosted target, so no Cargo feature removes
+/// them. They land on whichever thread parses the first object, which under the parallel
+/// harness is a race between this file's tests; parsing a trivial object here makes every
+/// window start after that initialization on this thread, independent of sibling scheduling.
+fn warm_process_lifetime_statics() {
+    let _ = session::parse_session_json(r#"{"warm":0}"#);
+}
+
 fn begin() {
+    warm_process_lifetime_statics();
     // Initialize the thread-local keys before observation is armed.
     ACTIVE.set(false);
     ALLOCATIONS.set(0);

docs/REALTIME_DEPENDENCY_POLICY.md

@@ -343,7 +343,12 @@ Parser allocation and diagnostic formatting are expected control-plane behavior.
 returns typed diagnostics; arithmetic and configured-cap preflight runs before the canonical string,
 model clone, normalized indexes, or downstream plan work. JSON string and duplicate-key
 fixtures, the strict unknown-key matrix, target compilation, and parser/compiler fuzz targets are
-the compatibility and failure-mode evidence for this dependency choice.
+the compatibility and failure-mode evidence for this dependency choice. `json-syntax`'s object
+indexing goes through `hashbrown` 0.12's default hasher, `ahash` 0.7's `RandomState`, which on its
+first construction in a process lazily allocates 88 bytes of process-lifetime heap and seeds from
+OS entropy per process -- harmless to every shipped cap (they are explicit row sums), but relevant
+to any exact allocator oracle that arms across the first object parse in a process (see
+`crates/capi/tests/resource_lifecycle.rs`).
 
 The earlier issue-004 cross-target archive sizes are historical measurements for the retired
 parser stack and are not projected onto the JSON implementation. Current size and allocation