feat(ops): ingest Axon monitor alerts and incident debug bundles

[05F3759DF]

Context

Axon issues #82 and #86 add monitor alerts and incident debug bundles on the robot side. Keystone needs the paired ingestion and indexing surface so operators can see alerts centrally and find debug artifacts associated with robots, tasks, episodes, and incidents.

Related Axon issues:

• feat(system): integrate monitor alerts with operations pipeline axon#82
• feat(recorder): create incident debug bundle axon#86

Scope

• Add an API or ingestion path for Axon monitor alerts with severity, category, source component, robot identifier, timestamps, and compact context.
• Store alert history and associate alerts with robots, workstations, tasks, batches, episodes, and incidents where possible.
• Add a debug bundle manifest model with object paths, hashes, bundle type, created_at, source component, and linked operational entities.
• Expose alert and debug bundle information through operator-facing APIs.
• Ensure sensitive values are not stored or returned in alert and bundle metadata.
• Allow incidents to reference relevant Axon debug bundles.

Acceptance Criteria

• Keystone can receive and persist Axon monitor alerts.
• Keystone can register debug bundle manifests without requiring the bundle contents to be parsed immediately.
• Operators can query alerts and bundles by robot, task, episode, incident, severity, and time range.
• Alert and bundle payloads are redacted for sensitive values.
• Tests cover alert ingestion, bundle registration, entity linking, and redaction.