caddy + pihole: make both boot-persistent and self-healing

Caddy left compose.yaml for a quadlet unit (caddy.service): joins
dankclaw_default for container-name upstreams, Pull=never for the local-only
image, Porkbun credentials via /home/dank/Containers/caddy/env written by
deploy from .env, bare-IP-catch-all health check. deploy_caddy installs,
enables, and starts the unit after retiring the bare container (state is in
host volumes).

Pi-hole: the repo now owns the sysctl drop-in
(dankclaw/pihole/sysctl/99-dnsmasq.conf, ip_unprivileged_port_start=53);
deploy_pihole installs it to /etc/sysctl.d/, stages conflicting later-sorted
drop-ins in the home trash, and applies 'sysctl --system' (the boot code
path). This fixes the 2026-08-26 crash loop (port-53 bind denied, restart
counter 1645) caused by a second drop-in resetting the value to 80.

Tests: new caddy_quadlet.bats seam; caddyfile/deployment_flow assertions
repointed from the removed compose service to the quadlet; pihole.bats pins
the sysctl drop-in and its deployment; test-changed.sh routes dankclaw/caddy/
and the pihole subtree to their seams. Docs: Caddy, Pi-hole, Dankclaw Stack,
work log.

docs/log.md

@@ -30,3 +30,10 @@ timestamp: 2026-09-14
 - `/scripts/deploy.sh` and `/scripts/deploy-remote.sh` — Removed standalone proxy dispatch and added idempotent retirement before canonical Caddy deployment.
 - `/tests/caddyfile.bats`, `/tests/deployment_scoping.bats`, `/tests/deployment_flow.bats`, `/tests/frank_large_config.bats` — Added migration coverage and corrected the existing ubatch harness assertion.
 - `/docs/index.md` — Bundle index remains the root navigation entry for the updated pages.
+- **Boot-persistence audit (post-reboot, 2026-08-26 evening):** after Frank's reboot, Caddy and Pi-hole were both down. Caddy ran as a bare compose container (`restart: unless-stopped` does not survive shutdown's explicit stop; rootless Podman has no boot-time auto-start for bare containers). Pi-hole's quadlet existed but crash-looped (restart counter 1645): a later-sorted sysctl drop-in (`99-rootless-ports.conf`) reset `net.ipv4.ip_unprivileged_port_start` to 80, so the rootless port-53 publish failed with `bind: permission denied`.
+- `/AGENTS.md` — new MANDATORY section "Boot Persistence & Self-Healing": every deployed, proven-working container must have a self-healing, boot-persistent quadlet unit (`WantedBy=default.target` + enabled + linger, `Restart=always`, repo-provenance `.container`), verified before a service is declared deployed.
+- `/dankclaw/caddy/quadlet/caddy.container`, `/dankclaw/caddy/env.example` — Caddy is now a boot-persistent quadlet (`caddy.service`): joins `dankclaw_default` so container-name upstreams keep resolving, `Pull=never` (local-only image), Porkbun credentials via `/home/dank/Containers/caddy/env` (deploy writes it from `.env`), bare-IP-catch-all health check. The caddy service was removed from `/dankclaw/compose.yaml`.
+- `/dankclaw/pihole/sysctl/99-dnsmasq.conf` — repo source of truth for `ip_unprivileged_port_start=53`; `deploy_pihole` installs it to `/etc/sysctl.d/`, stages conflicting later-sorted drop-ins in the home trash, and applies `sysctl --system` (the boot code path).
+- `/scripts/deploy-remote.sh` — `deploy_caddy` installs/enables/starts the quadlet (retiring the bare container; all state is in host volumes); `deploy_pihole` enforces the sysctl prerequisite.
+- `/tests/caddy_quadlet.bats` (new seam), `/tests/caddyfile.bats`, `/tests/deployment_flow.bats`, `/tests/pihole.bats` — quadlet boot-persistence, self-healing, network, env, and sysctl coverage; compose assertions repointed from the removed caddy service to the quadlet.
+- `/docs/Infrastructure/Caddy.md`, `/docs/Infrastructure/Pi-hole.md`, `/docs/Dankclaw/Dankclaw Stack.md` — quadlet runtime facts, the 2026-08-26 incident, and the sysctl-conflict failure mode.