Unpin Superseded Contract Codes (3/4)

Original Proposal Text

## Summary Pinned contract codes stay resident in every node's memory. Over successive protocol releases the Nolus Pirin mainnet has accumulated 345 pinned code IDs, of which only 17 back live contracts today: the platform contracts Treasury (911), Timealarms (912) and Admin (913), and the current `SOLANA-METIS-USDC` (921–927) and `SOLANA-METIS-SOL` (928–934) protocol contracts. The codes stored for the pending v0.9.1 currency update (935–941) are pinned by their own proposal. This is part 3 of 4 of the cleanup; each part unpins a batch of superseded code IDs, because unpinning loads every module at proposal simulation and a single proposal covering all 328 codes exceeds the block gas limit. This part unpins 82 code IDs (747–783, 785–829). Each is a superseded release of a platform or protocol contract; no active contract is instantiated from any of them — the only instances left on these codes are closed leases, which never execute again. Unpinning frees node memory and has no effect on contract state or on any contract's ability to execute; an unpinned code is still loaded from storage on demand. By voting "YES" to this proposal you agree to unpin these superseded contract code IDs.