sdk(P2.2): typed compliance events + attest/session + Article 12 report

Typed events as SDK-side conventions (no backend change): ModelDecision /
HumanOverride / IncidentReport (NIS2 field names) / DataAccess as Python
dataclasses, TypeScript builders, and Go structs — each serializing to a plain
payload with regulation_refs (EU AI Act Art.12/14, NIS2 Art.23, AI-Act Art.62,
GDPR Art.30/6) and self-validating against the committed-payload number policy.

Python ergonomics: @attest(client, stream_id=...) wraps any function — one
event per call with commitments over args/kwargs and result (raw values never
leave the process), .last_receipt on the wrapper, exceptions log an
IncidentReport-shaped event (commitment over the traceback) and re-raise;
logging failures never break the workload (log-and-continue; strict=True is
the only raising mode — all test-enforced). session(...) groups typed events
under shared session_id/actor_ref metadata.

Evidence report: attesto.reports.article12(...) in Python and
`attesto report article12 --stream ... --output report.md` in the Go CLI —
deterministic templating (never LLM-generated) built only from existing tenant
endpoints: Art.12(2) coverage table, per-type event counts, P1.3 completeness
verdict, checkpoint -> anchor-tx -> block path, and replayable verification
commands. Claims discipline test-enforced in both languages: the words
"compliant"/"compliance guaranteed" never appear — the report states evidence
recorded and independently verifiable. The mock emulators now expose
event_type in tenant listings so report tests run end-to-end against P2.3.

Sweep green: Python 94, TS 59, Go all packages.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

events.go

@@ -0,0 +1,135 @@
+package attesto
+
+// [P2.2] Typed compliance events — SDK-side conventions, no backend change.
+// Each ToPayload() returns a plain payload map with regulation_refs included,
+// validated against the committed-payload number policy. Recording these never
+// claims conformity: Attesto attests records.
+
+// Typed event type identifiers.
+const (
+	EventTypeModelDecision  = "attesto.model_decision"
+	EventTypeHumanOverride  = "attesto.human_override"
+	EventTypeIncidentReport = "attesto.incident_report"
+	EventTypeDataAccess     = "attesto.data_access"
+)
+
+// Regulation references per typed event (conventions for reports/auditors).
+var (
+	RefsModelDecision  = []string{"EU-AI-Act:Art.12", "EU-AI-Act:Art.14"}
+	RefsHumanOverride  = []string{"EU-AI-Act:Art.14"}
+	RefsIncidentReport = []string{"NIS2:Art.23", "EU-AI-Act:Art.62"}
+	RefsDataAccess     = []string{"GDPR:Art.30", "GDPR:Art.6"}
+)
+
+func finishPayload(payload M, refs []string, extra M) (M, error) {
+	for key, value := range extra {
+		payload[key] = value
+	}
+	out := M{}
+	for key, value := range payload {
+		if value != nil && value != "" {
+			out[key] = value
+		}
+	}
+	out["regulation_refs"] = refs
+	if err := AssertCommitmentSafeNumbers(map[string]any(out), "$"); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// ModelDecision is one model-driven decision (commitments only; raw inputs and
+// outputs never leave your process).
+type ModelDecision struct {
+	Model            string
+	InputCommitment  map[string]string
+	OutputCommitment map[string]string
+	Decision         string
+	ConfidenceBp     int // basis points keep integers commitment-safe
+	HumanInLoop      bool
+	OperatorRef      string
+	Extra            M
+}
+
+func (e ModelDecision) EventType() string { return EventTypeModelDecision }
+
+func (e ModelDecision) ToPayload() (M, error) {
+	return finishPayload(M{
+		"model":             e.Model,
+		"input_commitment":  orNil(e.InputCommitment),
+		"output_commitment": orNil(e.OutputCommitment),
+		"decision":          e.Decision,
+		"confidence_bp":     e.ConfidenceBp,
+		"human_in_loop":     e.HumanInLoop,
+		"operator_ref":      e.OperatorRef,
+	}, RefsModelDecision, e.Extra)
+}
+
+// HumanOverride records a human overriding a model decision (Art. 14).
+type HumanOverride struct {
+	OriginalEventRef        string
+	OperatorRef             string
+	JustificationCommitment map[string]string
+	NewDecision             string
+	Extra                   M
+}
+
+func (e HumanOverride) EventType() string { return EventTypeHumanOverride }
+
+func (e HumanOverride) ToPayload() (M, error) {
+	return finishPayload(M{
+		"original_event_ref":       e.OriginalEventRef,
+		"operator_ref":             e.OperatorRef,
+		"justification_commitment": orNil(e.JustificationCommitment),
+		"new_decision":             e.NewDecision,
+	}, RefsHumanOverride, e.Extra)
+}
+
+// IncidentReport is a reportable incident with NIS2-style field names.
+type IncidentReport struct {
+	Severity          string
+	Category          string
+	DetectedAt        string
+	SummaryCommitment map[string]string
+	AffectedService   string
+	Extra             M
+}
+
+func (e IncidentReport) EventType() string { return EventTypeIncidentReport }
+
+func (e IncidentReport) ToPayload() (M, error) {
+	return finishPayload(M{
+		"severity":           e.Severity,
+		"category":           e.Category,
+		"detected_at":        e.DetectedAt,
+		"summary_commitment": orNil(e.SummaryCommitment),
+		"affected_service":   e.AffectedService,
+	}, RefsIncidentReport, e.Extra)
+}
+
+// DataAccess records an access to personal or regulated data.
+type DataAccess struct {
+	SubjectRefCommitment map[string]string
+	Purpose              string
+	LegalBasis           string
+	AccessorRef          string
+	Extra                M
+}
+
+func (e DataAccess) EventType() string { return EventTypeDataAccess }
+
+func (e DataAccess) ToPayload() (M, error) {
+	return finishPayload(M{
+		"subject_ref_commitment": orNil(e.SubjectRefCommitment),
+		"purpose":                e.Purpose,
+		"legal_basis":            e.LegalBasis,
+		"accessor_ref":           e.AccessorRef,
+	}, RefsDataAccess, e.Extra)
+}
+
+func orNil(m map[string]string) any {
+	if len(m) == 0 {
+		return nil
+	}
+	return m
+}