fix: major build system improvements and container output issues

- Fix container output visibility with proper TTY handling and debug mode
- Fix build order: kernel modules built before initramfs creation
- Implement two-stage kernel build to resolve chicken-and-egg dependency
- Fix sed command issues in kernel configuration with direct execution
- Add diffutils package to container for proper kernel build support
- Enhance NIC module/firmware correlation with intelligent selection
- Fix module staging logic: all NICs loaded in stage1 before network up
- Add smart firmware installation based on module requirements
- Create comprehensive function documentation (scripts/functionlist.md)
- Add debug container script for troubleshooting

Major fixes:
* Container builds now show real-time output
* Kernel builds work with proper GNU diff support
* Module/firmware selection optimized for common hardware
* Build process handles dependencies correctly
* Documentation provides complete function reference

scripts/lib/components.sh

@@ -49,11 +49,11 @@ function components_parse_sources_conf() {
     components_download_git "mycelium" "https://github.com/threefoldtech/mycelium" "v0.6.1" "$components_dir"
     components_build_component "mycelium" "build_mycelium" "$components_dir"
     
-    # Component 3: rfs
+    # Component 3: rfs (pre-built release)
     component_count=$((component_count + 1))
-    log_info "Processing component ${component_count}: rfs (git)"
-    components_download_git "rfs" "https://github.com/threefoldtech/rfs" "development" "$components_dir"
-    components_build_component "rfs" "build_rfs" "$components_dir"
+    log_info "Processing component ${component_count}: rfs (release)"
+    components_download_release "rfs" "https://github.com/threefoldtech/rfs/releases/download/v2.0.6/rfs" "v2.0.6" "$components_dir" ""
+    components_build_component "rfs" "install_rfs" "$components_dir"
     
     # Component 4: corex
     component_count=$((component_count + 1))
@@ -397,6 +397,32 @@ function build_mycelium() {
     log_info "Installed mycelium binary (${binary_size}) to: ${INSTALL_DIR}/usr/bin/mycelium"
 }
 
+# Install function for rfs (pre-built binary)
+function install_rfs() {
+    local name="$1"
+    local component_dir="$2"
+    
+    section_header "Installing rfs binary"
+    
+    log_info "Installing rfs from: ${component_dir}"
+    
+    # Find the rfs binary
+    local binary_path="${component_dir}/rfs"
+    if [[ ! -f "$binary_path" ]]; then
+        log_error "rfs binary not found at: ${binary_path}"
+        return 1
+    fi
+    
+    # Make executable and install
+    safe_execute chmod +x "$binary_path"
+    safe_mkdir "${INSTALL_DIR}/usr/bin"
+    safe_execute cp "$binary_path" "${INSTALL_DIR}/usr/bin/rfs"
+    safe_execute chmod +x "${INSTALL_DIR}/usr/bin/rfs"
+    
+    local binary_size=$(get_file_size "${INSTALL_DIR}/usr/bin/rfs")
+    log_info "Installed rfs binary (${binary_size}) to: ${INSTALL_DIR}/usr/bin/rfs"
+}
+
 # Install function for corex (pre-built binary)
 function install_corex() {
     local name="$1"
@@ -490,4 +516,6 @@ export -f components_parse_sources_conf
 export -f components_download_git components_download_release components_process_extra_options
 export -f components_build_component components_setup_rust_env
 export -f build_zinit build_rfs build_mycelium install_corex
-export -f components_verify_installation components_cleanup
+export -f components_verify_installation components_cleanup
+# Export functions for install_rfs
+export -f install_rfs