Run the kiosk on Chromium, and take the stray media server off musicdolphin

Chromium: same page, same machine, idle, Firefox 24.2% of a core against Chromium's
11.4%. The build comes from archive.raspberrypi.com (a "+rpt" version) and is patched
for this board's V3D GPU; Debian ships a much older chromium, so the archive matters.
The whole userland here is 32-bit armhf on a 64-bit kernel, which Firefox handles worse
than Chromium does. --use-gl=egl, --enable-gpu-rasterization, --ignore-gpu-blocklist
and --enable-zero-copy are what keep rasterization on the GPU: Chromium's blocklist
does not recognise this driver and silently falls back to software without them.
pi_kiosk_browser: firefox still works, as the fallback if an update ever regresses.

Debug mode also gains xdotool, scrot and --remote-debugging-port=9222 (on 127.0.0.1),
because firing XTEST key events at a window lands about half the time and a benchmark
you cannot verify the state of is worse than none.

pi_squeezeserver gains an absent path, and mediapis.yml derives its state from
mediapi_has_squeezeserver, which defaults to false for the whole group. false means
"actively remove", not "skip": musicdolphin has been running a Logitech Media Server
that no playbook installs and nothing talks to - every squeezelite in the fleet points
at pi_squeezelite_squeezeserver (192.168.178.80, the server) - while costing ~30 MB
resident and ~47 MB of swap on a 2 GB Pi that also drives the kiosk. The absent path
stops it, purges the package, unregisters it from sysdweb, drops the port 80 -> 9000
redirect and deletes its database and logs.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

roles/pi_squeezeserver/tasks/absent.yml

@@ -0,0 +1,60 @@
+---
+# The mirror image of present.yml. Worth having as a real code path rather than a
+# one-off ssh session: musicdolphin had LMS running because some earlier provisioning
+# put it there, no playbook has installed it since, and nothing on the network used
+# it - every squeezelite in the fleet points at `pi_squeezelite_squeezeserver`
+# (192.168.178.80, the server), not at the pi it happens to be running on. On a 2 GB Pi
+# that is also driving a kiosk browser, a stray Perl daemon holding ~30 MB resident and
+# ~47 MB of swap is worth reclaiming.
+
+- name: Check whether the Logitech Media Server unit is there at all
+  ansible.builtin.stat:
+    path: /lib/systemd/system/logitechmediaserver.service
+  register: pi_squeezeserver_unit
+
+- name: Stop and disable the Logitech Media Server
+  # Before the package goes, so systemd is told rather than left holding a unit file
+  # that vanishes underneath it.
+  ansible.builtin.systemd:
+    name: logitechmediaserver
+    state: stopped
+    enabled: false
+  when: pi_squeezeserver_unit.stat.exists
+
+- name: Purge the Logitech Media Server package
+  ansible.builtin.apt:
+    name: logitechmediaserver
+    state: absent
+    purge: true
+    autoremove: true
+
+- name: Drop the Logitech Media Server from sysdweb
+  # Same marker pi_sysdweb writes, so this removes exactly the block that role added.
+  ansible.builtin.blockinfile:
+    path: /etc/sysdweb.conf
+    marker: "# {mark} ansible managed for logitechmediaserver"
+    state: absent
+  notify: Restart sysdweb after dropping the LMS entry
+
+- name: Undo the port 80 -> 9000 redirect the install added
+  ansible.builtin.iptables:
+    table: nat
+    chain: PREROUTING
+    in_interface: eth0
+    protocol: tcp
+    match: tcp
+    destination_port: "80"
+    jump: REDIRECT
+    to_ports: "9000"
+    comment: Redirect web traffic to port 9000
+    state: absent
+
+- name: Remove the server's database and logs
+  # apt purge takes /usr/share/squeezeboxserver (118 MB) with it but leaves these. They
+  # are a scan cache and a log of a server nobody talked to.
+  ansible.builtin.file:
+    path: "{{ item }}"
+    state: absent
+  loop:
+    - /var/lib/squeezeboxserver
+    - /var/log/squeezeboxserver