fix: address multiple bugs from code review

- teardown_all.sh: replace `yes |` pipeline with `< <(yes)` process
  substitution to avoid SIGPIPE (exit 141) false failures under pipefail
- phase6_teardown.sh: extract push mirror `.id` instead of `.remote_name`
  to match the DELETE /push_mirrors/{id} API contract
- phase5_migrate_pipelines.sh: expand sed regex from `[a-z_]*` to
  `[a-z_.]*` to handle nested GitHub contexts like
  `github.event.pull_request.number`
- lib/common.sh: render_template now requires explicit variable list to
  prevent envsubst from eating Nginx variables ($host, $proxy_add_...)
- backup scripts: remove MacBook relay, use direct Unraid↔Fedora SCP;
  fix dump path to write to /data/ (mounted volume) instead of /tmp/
  (container-only); add unzip -t integrity verification
- preflight.sh: add --skip-port-checks flag for resuming with
  --start-from (ports already bound by earlier phases)
- run_all.sh: update run_step to pass extra args; use --skip-port-checks
  when --start-from > 1
- post-checks (phase4/7/9): wrap API calls in helper functions with
  >/dev/null redirection instead of passing -o /dev/null as API data
- phase8: replace GitHub archiving with [MIRROR] description marking
  and disable wiki/projects/Pages (archived repos reject push mirrors)
- restore_to_primary.sh: add require_vars for Fedora SSH variables

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

run_all.sh

@@ -69,11 +69,13 @@ record_step() {
   STEP_RESULTS+=("$result")
 }
 
-# Run a script, record pass/fail, stop on failure
+# Run a script, record pass/fail, stop on failure.
+# Usage: run_step "Step Name" "script.sh" [args...]
 run_step() {
   local name="$1" script="$2"
+  shift 2
   log_info ">>> Running: ${name}"
-  if "${SCRIPT_DIR}/${script}"; then
+  if "${SCRIPT_DIR}/${script}" "$@"; then
     record_step "$name" "PASS"
     printf '\n'
   else
@@ -126,9 +128,16 @@ fi
 # ---------------------------------------------------------------------------
 # Preflight — always runs (validates .env and infrastructure)
 # Even with --start-from, preflight ensures the environment is healthy.
+# When resuming (--start-from > 1), port-free checks are skipped because
+# earlier phases have Gitea already running on those ports.
 # ---------------------------------------------------------------------------
 log_info "=== Preflight ==="
-run_step "Preflight checks" "preflight.sh"
+if [[ "$START_FROM" -gt 1 ]]; then
+  log_info "Resuming from phase ${START_FROM} — skipping port-free checks"
+  run_step "Preflight checks" "preflight.sh" --skip-port-checks
+else
+  run_step "Preflight checks" "preflight.sh"
+fi
 
 # ---------------------------------------------------------------------------
 # Phases 1-9 — run sequentially, each followed by its post-check