Human classification corrections

Duckbill™ treats a user override of intent, attention, or priority as the current Classification. The AI suggestion stays in AIInference history.

Flow

USER CorrectClassification
  → evaluatePolicy(actor: USER, action: classify)
  → insert classifications (source_type = human)
  → designate current_classifications
  → insert human_corrections + single_correction observation
  → insert-only AuditEvent (actor, old/new, reason)

One correction does not create an ACTIVE rule. created_active_rule is always false and the database rejects true.

Current pointer

current_classifications is the user-visible Classification, keyed by mail_message_id + dimension. Reprocessing inserts a new AI row; it does not erase the human pointer. getConversation returns this pointer so the next GetConversation shows the override.

MailMessage is the logical target. MessageInstance is not updated.

HTTP

Method	Route	Purpose
POST	`/api/corrections`	Persist override
GET	`/api/corrections/conversation?conversationId=&mailMessageId=`	Classification slice for GetConversation

These routes are not the Home / Needs Me list APIs (MAIL-76).

See ADR 0024.