fix(ci): repair aspect_tests.sh grep-count bash bug (baseline rot) (#118)

## Summary

Restores the `Aspect — Thread Safety + ABI Contract + SPDX` check to
green. The check has been red on `main` for some time, gating every PR.

## Root cause

```
tests/aspect_tests.sh: line 77: [[: 0
0: syntax error in expression (error token is "0")
```

The pattern `has_export=$(grep -c 'pattern' file 2>/dev/null || echo
"0")` is broken: `grep -c` always prints the count (including `0` for no
matches) **and** exits non-zero when there are no matches. So `|| echo
"0"` also fires, and `has_export` ends up `"0\n0"`. The next line — `[[
"$has_export" -gt 0 ]]` — chokes on the embedded newline in arithmetic
context.

## Fix

Swap `|| echo "0"` → `|| true` at all 4 call-sites (lines 74, 75, 98,
99). `grep -c` already prints `0` cleanly; the `|| true` just suppresses
the exit code so `set -euo pipefail` doesn't abort the script.

## What's held out of this PR

The companion `.github/workflows/e2e.yml` fix — bump Zig `0.15.0` →
`0.15.1` (matches `.tool-versions`, retired upstream) and refresh the
`denoland/setup-deno` SHA pin (`5fae568d…` no longer resolves;
repointing to v2.0.4's `667a34cd…` SHA which `publish.yml` already uses)
— is **held out** because the current OAuth token lacks the `workflow`
scope GitHub requires for workflow-file edits. Will land in a follow-up
PR once the token is rotated, or you can apply those 4 line-edits
directly.

The `governance / Language / package anti-pattern policy` failure is
also red on main, but a parallel session is already diagnosing it under
the Estate-drift-remediation 2026-05 campaign. Not touched here per
`[[parallel-session-branch-drift]]`.

## Test plan

- [x] `bash -n tests/aspect_tests.sh` — syntax clean.
- [ ] CI runs `Aspect — Thread Safety + ABI Contract + SPDX` green on
this PR.
- [ ] No regression in the test's pass/fail logic for repos that
*should* fail it (cartridges with C-ABI exports + no Mutex).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

tests/aspect_tests.sh

@@ -71,8 +71,8 @@ for zigfile in "$zig_ffi_dir"/*.zig; do
             ;;
     esac
 
-    has_export=$(grep -cP '(?:pub )?export fn' "$zigfile" 2>/dev/null || echo "0")
-    has_mutex=$(grep -c 'Mutex' "$zigfile" 2>/dev/null || echo "0")
+    has_export=$(grep -cP '(?:pub )?export fn' "$zigfile" 2>/dev/null || true)
+    has_mutex=$(grep -c 'Mutex' "$zigfile" 2>/dev/null || true)
 
     if [[ "$has_export" -gt 0 && "$has_mutex" -eq 0 ]]; then
         fail "$basename_zig has $has_export C-ABI exports but no Mutex"
@@ -95,8 +95,8 @@ for cart_dir in "$PROJECT_DIR"/cartridges/*/ffi; do
     fi
 
     if [[ -n "$ffi_zig" ]]; then
-        has_export=$(grep -c 'pub export fn' "$ffi_zig" 2>/dev/null || echo "0")
-        has_mutex=$(grep -c 'Mutex' "$ffi_zig" 2>/dev/null || echo "0")
+        has_export=$(grep -c 'pub export fn' "$ffi_zig" 2>/dev/null || true)
+        has_mutex=$(grep -c 'Mutex' "$ffi_zig" 2>/dev/null || true)
 
         if [[ "$has_export" -gt 0 && "$has_mutex" -eq 0 ]]; then
             fail "$cart_name FFI: $has_export exports, no Mutex"