backup(books-vds): daily 06:00 MSK pipeline to kreknin live 🟢

- scripts/books-vds-backup-daily-kreknin/ — run.sh + .env.example + README
- ES path.repo bootstrap (one-time stack edit, snapshot repo 'kreknin' registered)
- curl smtps://yandex:465 email (CRLF + Date headers, no msmtp dep on CentOS 7)
- StrictHostKeyChecking=yes + pre-populated known_hosts (CentOS 7 no accept-new)
- cron /etc/cron.d/books-vds-backup live, initial sync 4.87 GB in 13m28s, ntfy push sent
- wiki: entities/books-vds.md + sources/books-vds-backup-daily-kreknin-2026-05-25.md created
- wiki: concepts/books-ssh-access → vds-kzntsv-ssh-access (was lying about books on vds-kzntsv)
- .tasks/books-vds-backup-daily-kreknin.md closed 🟢 pending phone-side verify

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/books-vds-backup-daily-kreknin/.env.example

@@ -0,0 +1,34 @@
+# /opt/stacks/backup/.env on books VDS — sourced by run.sh
+# Live values are NOT in git; sourced from pass entries:
+#   pass show books-vds/full-env     → BOOKS_DB_* + BOOKS_MONGO_*
+#   pass show vds-kzntsv/full-env    → NTFY_*
+#   pass show snolla-smtp/full-env   → SMTP_* + OPS_NOTIFY_EMAIL
+#   pass show kreknin/full-env       → DEST_USER (vitya), DEST_HOST (195.19.90.188)
+
+# === Backup destination ===
+DEST_USER=vitya
+DEST_HOST=195.19.90.188
+DEST_BASE=/volume1/NetBackup/books-vds
+RETENTION_DAYS=7
+SSH_KEY=/opt/stacks/backup/kreknin-key
+
+# === DB creds (books VDS containers) ===
+BOOKS_DB_ROOT_PASSWORD=...
+BOOKS_MONGO_USERNAME=root
+BOOKS_MONGO_PASSWORD=...
+
+# === Elasticsearch snapshot repo (file-based, registered 2026-05-25) ===
+ES_SNAPSHOT_REPO=kreknin
+
+# === NTFY (shared channel — vds-backup topic; ntfy.vds.kzntsv.site) ===
+NTFY_URL=https://ntfy.vds.kzntsv.site
+NTFY_USER=...
+NTFY_PASS=...
+
+# === SMTP (Yandex relay, noreply@snolla.com) ===
+SMTP_HOST=smtp.yandex.ru
+SMTP_PORT=587
+SMTP_USER=noreply@snolla.com
+SMTP_PASS=...
+SMTP_FROM=noreply@snolla.com
+OPS_NOTIFY_EMAIL=...