PoA transition (Plan A): set REGEN emissions to zero (inflation_max = inflation_min = 0)

Original Proposal Text

The final step of the Proof-of-Authority transition (RFC #70), after #72 (honest blocks_per_year, passed) and #73 (max_validators 11, passed and in effect). One standard x/mint MsgUpdateParams — no chain upgrade, effective the moment it passes. THE MECHANISM: x/mint currently emits at the corrected 3.50% — about 8.39M REGEN a year on a 239.7M supply. That emission buys no security: min_commission is 0, so at current prices a validator's take from emission is measured in cents, and the curated authority set runs on infrastructure budgets and conviction either way. What emission actually does is move value from non-stakers to stakers, block by block. WHAT THIS CHANGES: three fields — inflation_max 3.50% to 0, inflation_min 3.50% to 0, inflation_rate_change to 0. Every other mint param is read live from the chain at build time and passed through untouched. Supply becomes fixed at ~239.7M REGEN. WHAT IT DOES NOT DO: it takes nothing from anyone. Delegations, unbonding, fees, slashing, and governance are untouched. Staking rewards from emission end — that is the point — and every holder keeps the share of supply they already have, permanently. A future MsgUpdateParams can reverse it if the network ever chooses to mint again. CONFIRM WITHOUT TRUSTING ME: take total supply at two heights a few days apart and annualize the difference. Today it shows ~3.50%; after this passes it shows zero. That is the whole proposal. Parameters: mint_denom: uregen inflation_rate_change: 0.000000000000000000 inflation_max: 0.000000000000000000 inflation_min: 0.000000000000000000 goal_bonded: 0.600000000000000000 blocks_per_year: 5604080 More details: https://forum.regen.network/t/regen-network-proof-of-authority-consensus-rfc/70