nx_social_recovery.nx

nx_social_recovery.nx -- ELDERLY-FRIENDLY recovery: split a user's 256-bit recovery secret across N trusted contacts (family) so ANY K of them can bring the user back in, and K-1 learn NOTHING. This REPLACES the 24-word BIP39 mnemonic the user would otherwise have to safeguard (and could lose) -- the user holds nothing; their family IS the backup. "Best security, least stress": no password to remember, no seed phrase to lose. Built on the sovereign Shamir primitive (nx_vault_shamir, GF(2^31-1)). That field splits ONE scalar < 2^31, so a 256-bit secret is split CHUNK-WISE: 32 bytes -> 11 big-endian chunks (ten 3-byte + one 2-byte, each < 2^24 < 2^31-1), each Shamir-split under the SAME contact x-coords. Reconstruct each chunk from K shares, reassemble the 32 bytes. The recovery secret = the BIP39 entropy behind nx_modern_auth_recover, so a quorum rebuilds exactly what's needed to reset the account -- no mnemonic ever handed to the user. license_tier: ORIGINAL