Add cross-machine sync tooling (clone/pull/push all module repos)

repos.txt + sync-*.sh let any machine (Mac or Windows/Git Bash) hydrate all 49
module repos and keep them in sync via GitHub+gitea. Pulls are fast-forward only
(never clobber local work); pushes send commits only and flag uncommitted repos.
See SYNC.md for the two-machine workflow.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

sync-push-all.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Push your committed work for the parent + every module repo to BOTH GitHub
+# (origin) and gitea. Only commits are pushed. Any repo that still has UNCOMMITTED
+# changes is flagged, so you can see exactly what has not been synced yet.
+# Run this after you finish working, once you have committed your changes.
+#
+#   bash sync-push-all.sh
+set -uo pipefail
+cd "$(dirname "$0")" || exit 1
+
+push_one() {
+  local d="$1"
+  local br; br=$(git -C "$d" symbolic-ref --short HEAD 2>/dev/null || echo main)
+  local flag=""
+  [ -n "$(git -C "$d" status --porcelain --untracked-files=no)" ] && flag="  [HAS UNCOMMITTED CHANGES - not pushed]"
+  local any=0
+  for r in origin gitea; do
+    git -C "$d" remote get-url "$r" >/dev/null 2>&1 || continue
+    any=1
+    if git -C "$d" push -q "$r" "$br" 2>/dev/null; then
+      echo "pushed: $d -> $r$flag"
+    else
+      echo "push FAILED (or nothing to push): $d -> $r$flag"
+    fi
+  done
+  [ "$any" = 0 ] && echo "no remotes: $d"
+}
+
+echo "== parent =="
+push_one .
+[ -f repos.txt ] || { echo "repos.txt not found"; exit 1; }
+echo "== modules =="
+while IFS= read -r f; do
+  case "$f" in ''|\#*) continue ;; esac
+  if [ -d "$f/.git" ]; then push_one "$f"; else echo "skip (not cloned): $f"; fi
+done < repos.txt