docs: add agent bootstrap and contract read router

rules/patterns/alpine-livecd/README.md

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+# Alpine LiveCD Pattern Notes
+
+This file keeps examples and rationale. The normative rules live in `contract.md`.
+
+## Minimal mkimage Profile
+
+```sh
+profile_<name>() {
+    arch="x86_64"
+    hostname="<hostname>"
+    apkovl="genapkovl-<name>.sh"
+    image_ext="iso"
+    output_format="iso"
+    kernel_flavors="lts"
+    initfs_cmdline="modules=loop,squashfs,sd-mod,usb-storage quiet"
+    initfs_features="ata base cdrom ext4 mmc nvme raid scsi squashfs usb virtio"
+    grub_mod="all_video disk part_gpt part_msdos linux normal configfile search search_label efi_gop fat iso9660 cat echo ls test true help gzio"
+    apks="alpine-base linux-lts linux-firmware-none ..."
+}
+```
+
+`arch` is the easiest field to miss. Without it, mkimage may silently skip the profile.
+
+## apkovl Placement
+
+`genapkovl-<name>.sh` must be in the current working directory when mkimage runs.
+
+Example:
+
+```sh
+cp "genapkovl-<name>.sh" ~/.mkimage/
+cp "genapkovl-<name>.sh" /var/tmp/
+cd /var/tmp
+sh mkimage.sh --workdir /var/tmp/work ...
+```
+
+## `/var/tmp` Build Root
+
+Use `/var/tmp` instead of `/tmp`:
+
+```sh
+export TMPDIR=/var/tmp
+cd /var/tmp
+sh mkimage.sh ...
+```
+
+On Alpine builders, `/tmp` is often a small tmpfs and firmware/modloop builds overflow it.
+
+## Cache Reuse
+
+Typical cache-preserving cleanup:
+
+```sh
+if [ -d /var/tmp/bee-iso-work ]; then
+    find /var/tmp/bee-iso-work -maxdepth 1 -mindepth 1 \
+        -not -name 'apks_*' \
+        -not -name 'kernel_*' \
+        -not -name 'syslinux_*' \
+        -not -name 'grub_*' \
+        -exec rm -rf {} +
+fi
+```
+
+The apkovl section should still be rebuilt every time.
+
+## Faster Squashfs
+
+```sh
+mkdir -p /etc/mkinitfs
+grep -q 'MKSQUASHFS_OPTS' /etc/mkinitfs/mkinitfs.conf 2>/dev/null || \
+    echo 'MKSQUASHFS_OPTS="-comp lz4 -Xhc"' >> /etc/mkinitfs/mkinitfs.conf
+```
+
+## Long-Running Builds
+
+```sh
+apk add screen
+screen -dmS build sh -c "sh build.sh > /var/log/build.log 2>&1"
+tail -f /var/log/build.log
+```
+
+## Firmware Reminder
+
+Typical extra firmware packages:
+
+- `linux-firmware-intel`
+- `linux-firmware-mellanox`
+- `linux-firmware-bnx2x`
+- `linux-firmware-rtl_nic`
+- `linux-firmware-other`