feat(kernel): shared ABI decoder+proofs, no-panic gate, syscall storm, kani on shrunk kernel

Makefile

@@ -32,14 +32,17 @@ clippy:
 test:
 	cargo test --workspace
 
+# CBMC can eat all RAM and take the desktop down with it; cap each run.
+KANI = systemd-run --user --scope -q -p MemoryMax=12G -p MemorySwapMax=0 cargo kani
+
 kani-types:
-	cargo kani -p types
+	$(KANI) -p types
 
 kani-domain:
-	cargo kani -p domain
+	$(KANI) -p domain
 
 kani-kernel:
-	cargo kani -p kernel
+	$(KANI) -p kernel
 
 kani: kani-types kani-domain kani-kernel