feat(iso): Step 8a — retire archipelago-reconcile systemd timer

BootReconciler (in-process, 30s interval, spawned from main.rs as of
Step 6 commit 48f08aa3) fully replaces the timer-driven bash
reconciliation path. Delete the systemd unit + timer and their
ISO-builder touchpoints.

Removed:
- image-recipe/configs/archipelago-reconcile.service
- image-recipe/configs/archipelago-reconcile.timer
- image-recipe/build-auto-installer-iso.sh L412-413 (COPY unit+timer)
- image-recipe/build-auto-installer-iso.sh L449 (systemctl enable)
- image-recipe/build-auto-installer-iso.sh L542-543 (cp to WORK_DIR)

Kept (intentionally):
- scripts/reconcile-containers.sh
- scripts/container-specs.sh

Reason: core/archipelago/src/api/rpc/package/update.rs still invokes
reconcile-containers.sh at two sites (OTA update + rollback paths).
Porting those call sites to ContainerOrchestrator::upgrade() requires
manifests for every container update.rs might touch — that scope
belongs in Step 8b. Until then the script stays on disk, just no
longer runs on a periodic timer.

No Rust code changes. cargo check -p archipelago clean, 6 pre-existing
warnings. Skipped full ISO rebuild validation per user decision —
edits are 5 textual deletions with zero behavioral ambiguity; Step 9
live hot-swap on .228 will catch any regression.

image-recipe/configs/archipelago-reconcile.service

@@ -1,14 +0,0 @@
-[Unit]
-Description=Archipelago Container Reconciliation
-After=archipelago.service
-
-[Service]
-Type=oneshot
-User=archipelago
-Environment="XDG_RUNTIME_DIR=/run/user/1000"
-Environment="HOME=/home/archipelago"
-Environment="PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
-ExecStart=/home/archipelago/archy/scripts/reconcile-containers.sh
-TimeoutStartSec=600
-StandardOutput=journal
-StandardError=journal

image-recipe/configs/archipelago-reconcile.timer

@@ -1,14 +0,0 @@
-[Unit]
-Description=Archipelago container reconciliation (periodic)
-
-[Timer]
-# First run 10 minutes after boot, then every 6 hours
-OnBootSec=10min
-OnUnitActiveSec=6h
-# Jitter to avoid load spikes
-RandomizedDelaySec=300
-# Run missed checks on boot
-Persistent=true
-
-[Install]
-WantedBy=timers.target