Bind lawful metadata harvesting to SourceOS import bridge events

[mdheller]

Context

ProCybernetica PR #59 establishes the first lawful metadata harvesting contract: doctrine, envelope schema, OAI-PMH-style fixtures, validator, and CI gate.

PR: SocioProphet/ProCybernetica#59

SourceOS binding goal

Implement the SourceOS-side contract for metadata harvest runs as import_bridge activity, not as hidden crawler/sync behavior.

Scope

• Add a SourceOS import bridge design note for lawful metadata harvesting.
• Model the harvester as an explicit actor, likely actor_type=import_bridge.
• Emit canonical event classes for:
  • harvest.plan.created
  • harvest.policy.evaluated
  • harvest.run.started
  • harvest.batch.sealed
  • harvest.cursor.advanced
  • harvest.anomaly.detected
  • harvest.run.completed
• Bind batch receipts to SourceOS trace/root event IDs.
• Preserve hashed cursor values; do not expose raw continuation tokens by default.
• Carry privacy class, retention class, classification, handling tags, and policy decision refs.

Acceptance criteria

• A synthetic three-batch OAI-PMH-style run can be represented as SourceOS events.
• A token loop requires an explicit resumption_token_loop anomaly.
• Completed resumable runs require terminal empty-token state.
• No harvested record is marked durable or canonical without validation and promotion refs.

Non-goal

Do not implement a live OAI-PMH network harvester in this issue. This is the SourceOS event/import-bridge binding.