SearXNG: define the gluetun+searxng+valkey trio as quadlet units

Converts the podman-compose SearXNG stack to boot-persistent quadlet units so
it survives a reboot (the compose deployment did not). searxng sets
Network=gluetun.container, which makes it reuse gluetun's network namespace so
outbound search traffic exits the WireGuard tunnel; it publishes no port of its
own (the port lives on gluetun). gluetun and valkey join a pinned searxng
network (10.89.2.0/24, DNS-enabled) so searxng reaches valkey by name.

Secrets stay in /opt/searxng/.env (mode 0600), referenced via [Service]
EnvironmentFile= so ${VAR} expands. Adds a bats seam asserting the netns
wiring, port placement, boot install, and that no secret material is tracked.

tests/searxng_quadlet.bats

@@ -0,0 +1,101 @@
+#!/usr/bin/env bats
+# Seam: SearXNG stack boot-persistence via Quadlet.
+#
+# The gluetun + searxng + valkey trio runs under systemd as quadlet units so it
+# survives a reboot (the podman-compose deployment did not). The crux: searxng
+# must reuse gluetun's network namespace (Network=gluetun.container) so its
+# outbound search traffic exits the WireGuard tunnel, while still reaching valkey
+# by name on the shared searxng network.
+
+load helpers
+
+QDIR="$REPO_ROOT/dankclaw/searxng/quadlet"
+
+@test "all four quadlet files exist" {
+    [ -f "$QDIR/searxng.network" ]
+    [ -f "$QDIR/gluetun.container" ]
+    [ -f "$QDIR/searxng.container" ]
+    [ -f "$QDIR/searxng-valkey.container" ]
+}
+
+@test "searxng reuses gluetun's network namespace (exits the tunnel)" {
+    grep -qE '^Network=gluetun\.container' "$QDIR/searxng.container" \
+        || { echo "searxng.container must set Network=gluetun.container"; return 1; }
+}
+
+@test "searxng publishes no port (the port lives on gluetun)" {
+    if grep -qE '^PublishPort=' "$QDIR/searxng.container"; then
+        echo "searxng.container must not set PublishPort (it shares gluetun's netns)"
+        return 1
+    fi
+    return 0
+}
+
+@test "gluetun publishes SearXNG on 8081:8080" {
+    grep -qE '^PublishPort=8081:8080' "$QDIR/gluetun.container" \
+        || { echo "gluetun.container must publish 8081:8080"; return 1; }
+}
+
+@test "gluetun has NET_ADMIN and the /dev/net/tun device" {
+    grep -qE '^CapAdd=NET_ADMIN' "$QDIR/gluetun.container" \
+        || { echo "gluetun.container must set CapAdd=NET_ADMIN"; return 1; }
+    grep -qE '^Device=/dev/net/tun' "$QDIR/gluetun.container" \
+        || { echo "gluetun.container must set Device=/dev/net/tun"; return 1; }
+}
+
+@test "valkey joins searxng.network and is reachable by the name valkey" {
+    grep -qE '^Network=searxng\.network' "$QDIR/searxng-valkey.container" \
+        || { echo "searxng-valkey.container must set Network=searxng.network"; return 1; }
+    grep -qE '^NetworkAlias=valkey' "$QDIR/searxng-valkey.container" \
+        || { echo "searxng-valkey.container must set NetworkAlias=valkey"; return 1; }
+}
+
+@test "gluetun joins searxng.network so searxng (in its netns) can reach valkey" {
+    grep -qE '^Network=searxng\.network' "$QDIR/gluetun.container" \
+        || { echo "gluetun.container must set Network=searxng.network"; return 1; }
+}
+
+@test "searxng.network pins a subnet that limiter.toml trusts as a proxy" {
+    # The pinned subnet must appear in limiter.toml trusted_proxies so the value
+    # stays stable across reboots (rootless podman otherwise reassigns the CIDR).
+    local subnet
+    subnet=$(grep -oE '^Subnet=[0-9./:]+' "$QDIR/searxng.network" | head -1 | cut -d= -f2)
+    [ -n "$subnet" ] || { echo "searxng.network must pin a Subnet="; return 1; }
+    grep -qF "'$subnet'" "$REPO_ROOT/shared/searxng/limiter.toml" \
+        || { echo "pinned subnet $subnet missing from limiter.toml trusted_proxies"; return 1; }
+}
+
+@test "every container unit feeds \${VAR} expansion via [Service] EnvironmentFile" {
+    # An EnvironmentFile in [Container] only lands in the ignored [X-Container]
+    # section and does not feed ${VAR} expansion. It must be in [Service].
+    local f
+    for f in gluetun searxng searxng-valkey; do
+        # The file must contain a [Service] section that sets EnvironmentFile=.
+        awk '/^\[Service\]/{s=1;next} /^\[/{s=0} s&&/EnvironmentFile=/{found=1} END{exit found?0:1}' \
+            "$QDIR/$f.container" \
+            || { echo "$f.container: [Service] must set EnvironmentFile="; return 1; }
+    done
+    return 0
+}
+
+@test "every container unit is installed for boot (WantedBy=default.target)" {
+    local f
+    for f in gluetun searxng searxng-valkey; do
+        grep -qE '^WantedBy=default\.target' "$QDIR/$f.container" \
+            || { echo "$f.container: [Install] must set WantedBy=default.target"; return 1; }
+    done
+    return 0
+}
+
+@test "no secret material in the quadlet files" {
+    # The units reference \${VAR} placeholders, never literal keys. A WireGuard
+    # key is a 44-char base64 string; none may appear in the tracked files.
+    local f
+    for f in "$QDIR"/*.container "$QDIR"/*.network; do
+        if grep -qE '[A-Za-z0-9+/]{44}=' "$f"; then
+            echo "$f: contains a secret-like value"
+            return 1
+        fi
+    done
+    has_no_leaked_secret "$QDIR/gluetun.container"
+}