feat: Implement complete Zero OS Alpine Initramfs Builder

- Complete bash framework with strict error handling
- Modular library system (docker, alpine, components, initramfs, kernel, testing)
- Rust component integration (zinit, rfs, mycelium) with musl targeting
- Rootless Docker/Podman support for GitHub Actions
- Centralized configuration in config/build.conf
- 2-stage module loading system
- Strip + UPX optimization for minimal size
- Complete zinit integration replacing OpenRC
- GitHub Actions CI/CD pipeline
- Comprehensive documentation and usage guides

Components:
- Latest stable kernel 6.12.44
- Alpine Linux 3.22 base
- ThreeFold components: zinit, mycelium, rfs, corex
- Target: ~8-12MB final initramfs.cpio.xz

config/modules.conf

@@ -0,0 +1,52 @@
+# 2-stage module loading specification for Zero-OS Alpine initramfs
+# Based on existing configs/modules-essential.list
+# Format: STAGE:MODULE_NAME:FIRMWARE_FILES (optional)
+
+# Stage 1: Critical boot modules (loaded early for basic functionality)
+stage1:virtio_net
+stage1:virtio_scsi
+stage1:virtio_blk
+stage1:virtio_pci
+stage1:e1000
+stage1:e1000e
+stage1:scsi_mod
+stage1:sd_mod
+stage1:ahci
+stage1:nvme
+
+# Stage 2: Extended hardware support (loaded after initial boot)
+stage2:igb
+stage2:ixgbe
+stage2:i40e
+stage2:ice
+stage2:r8169
+stage2:8139too
+stage2:8139cp
+stage2:bnx2
+stage2:bnx2x
+stage2:tg3
+stage2:b44
+stage2:atl1
+stage2:atl1e
+stage2:atl1c
+stage2:alx
+
+# Tunnel and container support
+stage2:tun
+stage2:overlay
+
+# Control Groups (cgroups) - essential for container management
+stage2:cgroup_pids
+stage2:cgroup_freezer
+stage2:cgroup_perf_event
+stage2:cgroup_device
+stage2:cgroup_cpuset
+stage2:cgroup_bpf
+stage2:memcg
+stage2:blkio_cgroup
+stage2:cpu_cgroup
+stage2:cpuacct
+stage2:hugetlb_cgroup
+stage2:net_cls_cgroup
+stage2:net_prio_cgroup
+stage2:devices_cgroup