feat(deploy): halkyon.li's forward through ramiel and its host at home (ADR 0039)

ramiel's HAProxy passes halkyon.li's TLS connections, unopened, through a
WireGuard tunnel to the instance at home, with the visitor's address in a
PROXY header, and everything else to ramiel's own Caddy, moved to the
loopback. Each end's nftables table lets the tunnel carry HAProxy's 443 and
the SSH jump's 22 alone, and nothing from home to ramiel.

The host at home: sshd with keys alone, the root disk unlocked over SSH at
boot (dropbear-initramfs, D20), Docker's and containerd's data bind-mounted
from the HDD, and home's end of the tunnel before Docker. An instance behind
the forward (compose.forwarded.yaml) publishes 443 on the tunnel's address
alone, trusts the PROXY header from ramiel alone, and gets its certificates
through TLS-ALPN, without HTTP/3.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

deploy/redeploy.sh

@@ -105,7 +105,7 @@ main() {
   # the container keeps the old one (found 2026-10-10). A changed Caddyfile, or a
   # sidecar's site, therefore recreates the container, which mounts the new file; the
   # certificates are in a volume, and the instance is away for seconds.
-  if ! git diff --quiet "$deployed" "$commit" -- Caddyfile 'sidecars/*.caddy'; then
+  if ! git diff --quiet "$deployed" "$commit" -- Caddyfile 'sidecars/*.caddy' forwarded.caddy; then
     docker compose up -d --force-recreate --no-deps caddy
   fi
   wait_until_answering server