fix(tests): POSIX arithmetic in e2e; prune Zig build dirs in aspect

- tests/e2e/lifecycle_e2e.sh: replace ((PASS++))/((FAIL++))/((SKIP++))
  with PASS=$((PASS+1)) etc. Under `set -euo pipefail` a post-increment
  of a 0-valued var returns exit 1 and aborted the script on the first
  check (same fix already present in the aspect test).
- tests/aspect/cross_cutting_test.sh: prune .zig-cache/ and zig-out/
  from the Zig SPDX `find` so a generated, header-less
  dependencies.zig left by `zig build` cannot skew the count when the
  test runs in an already-built tree.

https://claude.ai/code/session_01GJatEm2TVFSTBEkKXmserJ

Author: claude

tests/aspect/cross_cutting_test.sh

@@ -29,8 +29,11 @@ idr_total=$(find "${JK_DIR}/src/abi" -name '*.idr' 2>/dev/null | wc -l)
 idr_spdx=$(grep -rl 'SPDX-License-Identifier' "${JK_DIR}/src/abi" --include='*.idr' 2>/dev/null | wc -l)
 check "Idris2 SPDX headers (${idr_spdx}/${idr_total})" "[ '${idr_spdx}' -eq '${idr_total}' ]"
 
-zig_total=$(find "${JK_DIR}/ffi/zig" -name '*.zig' 2>/dev/null | wc -l)
-zig_spdx=$(grep -rl 'SPDX-License-Identifier' "${JK_DIR}/ffi/zig" --include='*.zig' 2>/dev/null | wc -l)
+# NB: prune Zig build artefacts (.zig-cache/, zig-out/) — `zig build` drops a
+# generated dependencies.zig in the cache with no SPDX header, which would
+# otherwise skew the count when this runs in a tree that has been built.
+zig_total=$(find "${JK_DIR}/ffi/zig" -type d \( -name '.zig-cache' -o -name 'zig-out' \) -prune -o -name '*.zig' -print 2>/dev/null | wc -l)
+zig_spdx=$(find "${JK_DIR}/ffi/zig" -type d \( -name '.zig-cache' -o -name 'zig-out' \) -prune -o -name '*.zig' -print 2>/dev/null | xargs -r grep -l 'SPDX-License-Identifier' 2>/dev/null | wc -l)
 check "Zig SPDX headers (${zig_spdx}/${zig_total})" "[ '${zig_spdx}' -eq '${zig_total}' ]"
 
 # --- Forbidden Patterns ---

tests/e2e/lifecycle_e2e.sh

@@ -13,8 +13,11 @@ SKIP=0
 TMPDIR="$(mktemp -d)"
 trap 'rm -rf "$TMPDIR"' EXIT
 
-check() { if eval "$2"; then echo "[PASS] $1"; ((PASS++)); else echo "[FAIL] $1"; ((FAIL++)); fi; }
-skip() { echo "[SKIP] $1"; ((SKIP++)); }
+# NB: use POSIX arithmetic assignment, not ((PASS++)) — under `set -e` a
+# post-increment whose old value is 0 returns exit status 1 and kills the
+# script after the very first check (matches tests/aspect/cross_cutting_test.sh).
+check() { if eval "$2"; then echo "[PASS] $1"; PASS=$((PASS+1)); else echo "[FAIL] $1"; FAIL=$((FAIL+1)); fi; }
+skip() { echo "[SKIP] $1"; SKIP=$((SKIP+1)); }
 
 echo "=== JanusKey E2E Lifecycle Test ==="