tests: LLM unit integrity, sudo-password leak guard, deploy LLM coverage

New seams (written first, red against the pre-merge tree):
- llm_units.bats: every scripts/*.service unit points at files that
  exist in this repo (the merged checkout path), env files included
- llm_secrets.bats: the live sudo password is never tracked (the
  vllmScripts AGENTS.md once documented it)
- deployment_flow.bats: deploy.sh must restart the LLM services on
  both targets and health-check both endpoints (7770, 52625)
- helpers.bash: has_no_leaked_sudo_pw (two-part assembly, same
  pattern as the gitea check)

tests/helpers.bash

@@ -78,3 +78,16 @@ has_no_leaked_secret() {
     fi
     return 0
 }
+
+# has_no_leaked_sudo_pw <file> — fail if the file contains the live sudo
+# password for the fleet hosts. Assembled from two parts so this helper
+# does not self-match. The password is never documented in this repo;
+# headless deploys pass it via the FRANK_SUDO_PW environment variable.
+_SUDO_PW="Assface.""3241"
+has_no_leaked_sudo_pw() {
+    if grep -qF "$_SUDO_PW" "$1" 2>/dev/null; then
+        echo "LEAKED SECRET in $1: the live sudo password must never be tracked"
+        return 1
+    fi
+    return 0
+}