Add post_progress_to_api lightweight telemetry ping

Introduce post_progress_to_api() in misc/api.func — a non-blocking, fire-and-forget curl ping (gated by DIAGNOSTICS and RANDOM_UUID) that updates telemetry status to "configuring". Wire this progress ping into multiple scripts (alpine-install.func, install.func, build.func, core.func) at key milestones (container start, network ready, customization, creation, cleanup) and replace/deduplicate some earlier post_to_api calls. Also update error_handler.func to always report failures immediately via post_update_to_api to ensure failures are captured even before/after container lifecycle.

misc/error_handler.func

@@ -204,6 +204,12 @@ error_handler() {
 
   printf "\e[?25h"
 
+  # ALWAYS report failure to API immediately - don't wait for container checks
+  # This ensures we capture failures that occur before/after container exists
+  if declare -f post_update_to_api &>/dev/null; then
+    post_update_to_api "failed" "$exit_code" 2>/dev/null || true
+  fi
+
   # Use msg_error if available, fallback to echo
   if declare -f msg_error >/dev/null 2>&1; then
     msg_error "in line ${line_number}: exit code ${exit_code} (${explanation}): while executing command ${command}"
@@ -254,11 +260,6 @@ error_handler() {
 
       # Offer to remove container if it exists (build errors after container creation)
       if [[ -n "${CTID:-}" ]] && command -v pct &>/dev/null && pct status "$CTID" &>/dev/null; then
-        # Report failure to API before container cleanup
-        if declare -f post_update_to_api &>/dev/null; then
-          post_update_to_api "failed" "$exit_code"
-        fi
-
         echo ""
         if declare -f msg_custom >/dev/null 2>&1; then
           echo -en "${TAB}❓${TAB}${YW}Remove broken container ${CTID}? (Y/n) [auto-remove in 60s]: ${CL}"