Complete module dependency fixes and build improvements

- Implement proper recursive dependency resolution using depmod -av + modinfo -k
- Copy configs/init as /sbin/init instead of creating symlink to zinit
- Fix validation to check /sbin/init as executable file (not symlink)
- Remove automatic cleanup - always preserve build artifacts for incremental builds
- Module resolution now finds missing core modules: virtio.ko, virtio_ring.ko, nvme-core
- Recursive resolution verified: nvme→nvme-core, virtio_scsi→5 dependencies
- Final chroot depmod creates proper module database for boot-time loading

scripts/lib/initramfs.sh

@@ -558,17 +558,17 @@ function initramfs_validate() {
         ((errors++))
     fi
     
-    # Check that /sbin/init is properly linked to zinit
-    if [[ -L "${initramfs_dir}/sbin/init" ]]; then
-        local link_target=$(readlink "${initramfs_dir}/sbin/init")
-        if [[ "$link_target" == "zinit" ]]; then
-            log_info "✓ /sbin/init correctly linked to zinit"
+    # Check that /sbin/init is configs/init script (not symlink)
+    if [[ -f "${initramfs_dir}/sbin/init" && -x "${initramfs_dir}/sbin/init" ]]; then
+        # Verify it's the configs/init script by checking content
+        if grep -q "ZERO-OS ALPINE INITRAMFS" "${initramfs_dir}/sbin/init" 2>/dev/null; then
+            log_info "✓ /sbin/init is configs/init script"
         else
-            log_error "✗ /sbin/init linked to wrong target: ${link_target}"
+            log_error "✗ /sbin/init is not configs/init script"
             ((errors++))
         fi
     else
-        log_error "✗ /sbin/init is not a symbolic link"
+        log_error "✗ /sbin/init is missing or not executable"
         ((errors++))
     fi