Operate OpenOT with InfluxDB 3

InfluxDB 3 HTTP writes cannot atomically advance the source checkpoint, so truST requires a bounded local SQLite spool. Canonical documents and checkpoint commit there first; remote writes drain in order. remote_pending > 0 means locally durable but not remotely acknowledged, and prevents ready.

Use the repository's examples/openot_database/influxdb3/ example for token/CA setup, SQL query, spool inspection, outage/recovery, backup, and cleanup. Set max_bytes above the spool schema footprint and leave filesystem headroom for WAL/allocation. Full spool rolls back the incoming batch and checkpoint and faults visibly.

The spool is initialized directly as schema generation 1. A markerless, incomplete, or differently marked pre-release spool is rejected without modification; back it up and recreate the development spool.

Back up both the Influx database and local spool consistently. Never delete or replace a nonempty spool during troubleshooting. Monitor spool pages, remote_pending, HTTP latency/errors, ring lag/loss, and free space. Test server/spool upgrades and restore on the exact supported InfluxDB 3 product.