fix(frank-archon): raise the ttm knob from a root ExecStartPre — User=dank cannot write it

a9da65e put the raise inside the serve script, which runs as `User=dank`: the
knob is root-owned 0644, so `-w` is false and the write silently failed — the
gate printed its refusal on a cap it had just failed to move. The privileged
path is systemd's `+` prefix: `ExecStartPre=+scripts/ttm-preflight.sh --raise`
runs as root even under `User=`, before ExecStart, so `Restart=always` can
never outrun it. The lib is now also executable (`--raise` sources the env file
and verifies), and keeps a `sudo -n` fallback for a human running the gate from
a shell.

Seam: the refusal cases run with a PATH that has `cat`+`bash` and NO `sudo`
(root writes a 444 file, so a passwordless dev box would have tested nothing),
and both now assert the gate's own exit 1, not merely non-zero. New seam covers
the unit line and the `--raise` entry point end to end (writable knob -> raised,
no args -> usage exit 2).

scripts/frank-archon.service

@@ -35,6 +35,13 @@ Group=dank
 LimitMEMLOCK=infinity
 Environment="FRANK_ARCHON_ENV_FILE=/home/dank/serverAppConfigs/scripts/frank-archon.env"
 ExecStart=/home/dank/serverAppConfigs/scripts/serve-frank-archon.sh
+# The `+` prefix runs this as root even though the service is User=dank — the
+# ttm pages cap is a root-owned knob and the pinned-RAM ledger (~147 GiB) is
+# unusable below it. After a reboot the knob is back at its default (half of
+# RAM), so the raise must be part of the start, not a note in a runbook: the
+# 2026-10-12 power failure reset it and the endpoint refused to boot 6,919
+# times. The serve script re-verifies the cap after this hook.
+ExecStartPre=+/home/dank/serverAppConfigs/scripts/ttm-preflight.sh --raise
 # systemd stop: wait alone cannot stop the container child; stop it
 # explicitly. No graceful drain contract is claimed (the OpenAI front end
 # holds no queue to drain — in-flight decodes are lost, which a stop