Add audit start and end dates to audits

ISO audits often span a window distinct from certificate validity.
Store optional audit_start_date and audit_end_date on the audit
record and expose them through GraphQL, MCP, CLI, n8n, and console.

Signed-off-by: Cursor Agent <cursoragent@cursor.com>

Co-authored-by: Bryan FRIMIN <bryan@frimin.fr>

pkg/server/api/mcp/v1/schema.resolvers.go

@@ -1499,6 +1499,8 @@ func (r *Resolver) AddAuditTool(ctx context.Context, req *mcp.CallToolRequest, i
 			Name:           input.Name,
 			ValidFrom:      input.ValidFrom,
 			ValidUntil:     input.ValidUntil,
+			AuditStartDate: input.AuditStartDate,
+			AuditEndDate:   input.AuditEndDate,
 			State:          input.State,
 			FrameworkID:    input.FrameworkID,
 		},
@@ -1527,6 +1529,8 @@ func (r *Resolver) UpdateAuditTool(ctx context.Context, req *mcp.CallToolRequest
 			Name:                       UnwrapOmittable(input.Name),
 			ValidFrom:                  input.ValidFrom,
 			ValidUntil:                 input.ValidUntil,
+			AuditStartDate:             input.AuditStartDate,
+			AuditEndDate:               input.AuditEndDate,
 			State:                      input.State,
 			CompliancePortalVisibility: input.CompliancePortalVisibility,
 		},