How can my common-law spouse and I prove that we have lived together for at least one uninterrupted year ?

Here are the kinds of proof that can be shown to the Canadian Border Services Agency officer when asking to enter Canada to seek asylum and to rejoin your common-law partner in Canada:
•         A statutory declaration of a common-law union
•          Statements for shared bank accounts
•          Shared credit cards
•          Proof of shared ownership of residential property
•          Shared residential leases
•          Shared rental receipts
•          Bills for shared utility accounts, such as electricity, gas, and telephone
•          Proof of shared management of household expenses
•          Evidence of shared purchases (especially of household items)
•          Mail addressed to either or both of you at the same address,
•         Important documents for both of you showing the same address, such as:
            Identification documents
            Driver's licenses
            Insurance policies
            Any other documents that show you have been living together.