Add beacon_bind Arcium circuit + anonbeta1 program with MPC binding

[FwazB]

• beacon_bind circuit: SHA3-256 commitment of rns_dest_hash + region_code computed inside Arcium MPC, returns encrypted u128 to owner
• anonbeta1 program: register_beacon, heartbeat (plain), plus 3 new Arcium instructions (init_comp_def, register_beacon_private, callback)
• PrivateBeaconRegistry PDA for encrypted beacon state
• Deployed to devnet: anon7uu8UtVoFgS8GCSfw2RqyphJhkN3xEjgPwznYDe
• MXE initialized, comp def registered on-chain (cluster offset 456)
• Circuit uploaded to Supabase storage bucket

[Magicred-1]

gm no need to registration fee anymore on beacons:

• Any Internet connected users is a beacon the Registry track the co-signed transactions.
• 1% on small amounts and dynamically decreases based on the transaction size volume.
• No need to keep the rns addresses since they can be rotated pretty easy which would break the data chain..
• Heartbeat is a good idea but it be replaced by a timestamp_last_cosign .. or something similar.
• Might be interesting to have stats to return to the user (beacon) such as the fees he's collected so far / the amounts of co-sign he've done so far and his LST Staking amount / Yield ..