Previously, the only way to unlock a wallet that had been saved in this
browser was to click Register (name or TLD), open the modal, and pick
'Unlock my browser wallet' from the wallet-choice step. From the nav
dropdown you could only start onboarding fresh (New / Import / WC).
profile-menu.js now checks localStorage for the BuiltInWallet's storage
key (bns.wallet.v1) at every render, and when a saved wallet is present
inserts a '🔓 Unlock my wallet' item at the top of the not-signed-in
dropdown — with a divider below it, so it reads as the primary action
and the Onboarding options stay available for adding a different wallet.
The dropdown click handler already lazy-loads register-flow.js and
calls window.siriusSignInWallet(action); register-flow.js's startSignIn
grew an 'unlock' mode that opens the modal directly at stepUnlock (the
password prompt). Same success path as every other sign-in: on unlock
success, siriusProfile is written and the modal closes with '✓ Signed
in' — the nav pill flips to the address without a reload.
Verified end-to-end on landing: saved wallet detected -> dropdown shows
Unlock as first item -> click -> password -> '✓ Signed in' -> pill
becomes 'qqyx49…zx8x seed ▾' with no reload. TLD mint from tld.html
also verified end-to-end: search 'e2etldtest' -> Register -> modal ->
Unlock -> password -> Fund -> Confirm (fee 1,250,000 sat + beacon dust
~1,300 sat) -> Register -> checking-availability -> loading-coins ->
'wallet is empty' (expected without chipnet funds; downstream code is
the same registerTldWithBuiltInWallet path the CLI uses).
afeae356aa