Don't do a single sig Hot wallet. Easy set up in Nunchuck, create a 2 of 2 multisig. Get an NFC card, load one key on the card and hide it in your (physical) wallet. (Make it innocuous too like a "bonus card" for a grocery store) then to spend out, use one key in the Nunchuck app and Tap the NFC card to your phone to sign the transaction.

Lightning is more hands on for a self-sovereign set up. You would need to run a full node, and a lightning node, and connect to peers, and open channels, and then you can use a phone client like nostr:nprofile1qqsrf5h4ya83jk8u6t9jgc76h6kalz3plp9vusjpm2ygqgalqhxgp9gpz4mhxue69uhk2er9dchxummnw3ezumrpdejqzyrhwden5te0dehhxarj9ekxzmnyqyt8wumn8ghj7un9d3shjtnwdaehgu3wvfskueq555fk2 to connect to your node.

OR you can use their LSP service and run their embedded node on your phone but all that backend is their domain so, there's a trust model involved.