feat: initial Phase 1 PoC scaffolding for KubeSolo OS

Complete Phase 1 implementation of KubeSolo OS — an immutable, bootable
Linux distribution built on Tiny Core Linux for running KubeSolo
single-node Kubernetes.

Build system:
- Makefile with fetch, rootfs, initramfs, iso, disk-image targets
- Dockerfile.builder for reproducible builds
- Scripts to download Tiny Core, extract rootfs, inject KubeSolo,
  pack initramfs, and create bootable ISO/disk images

Init system (10 POSIX sh stages):
- Early mount (proc/sys/dev/cgroup2), cmdline parsing, persistent
  mount with bind-mounts, kernel module loading, sysctl, DHCP
  networking, hostname, clock sync, containerd prep, KubeSolo exec

Shared libraries:
- functions.sh (device wait, IP lookup, config helpers)
- network.sh (static IP, config persistence, interface detection)
- health.sh (containerd, API server, node readiness checks)
- Emergency shell for boot failure debugging

Testing:
- QEMU boot test with serial log marker detection
- K8s readiness test with kubectl verification
- Persistence test (reboot + verify state survives)
- Workload deployment test (nginx pod)
- Local storage test (PVC + local-path provisioner)
- Network policy test
- Reusable run-vm.sh launcher

Developer tools:
- dev-vm.sh (interactive QEMU with port forwarding)
- rebuild-initramfs.sh (fast iteration)
- inject-ssh.sh (dropbear SSH for debugging)
- extract-kernel-config.sh + kernel-audit.sh

Documentation:
- Full design document with architecture research
- Boot flow documentation covering all 10 init stages
- Cloud-init examples (DHCP, static IP, Portainer Edge, air-gapped)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cloud-init/examples/portainer-edge.yaml

@@ -0,0 +1,26 @@
+# KubeSolo OS Cloud-Init — Portainer Edge Agent Integration
+# This config connects the KubeSolo node to a Portainer Business instance
+# via the Edge Agent for remote management.
+#
+# Place at: /mnt/data/etc-kubesolo/cloud-init.yaml
+
+hostname: edge-node-01
+
+network:
+  mode: dhcp
+
+kubesolo:
+  local-storage: true
+  # extra-flags: ""
+
+# Portainer Edge Agent configuration
+# After KubeSolo starts, deploy the Edge Agent as a workload
+portainer:
+  edge-agent:
+    enabled: true
+    # Get these values from Portainer → Environments → Add Environment → Edge Agent
+    edge-id: "your-edge-id-here"
+    edge-key: "your-edge-key-here"
+    portainer-url: "https://portainer.example.com"
+    # Optional: specify Edge Agent version
+    # image: portainer/agent:latest