Feat/mainnet genesis bootstrap

[rahulghangas]

Summary

• Add scripts/mainnet/genesis.sh to build the canonical mainnet genesis.json for opengradient_1486-1 from validators.yaml + foundation.yaml inputs. Idempotent, supports --dry-run, runs hard guards (zero inflation, zero community tax, finite max_gas, denom consistency, supply integrity, SVIP dormant), then evmd genesis validate.
• L1 genesis supply is intentionally minimal: 4 × 10 OPG = 40 OPG total (validator self-stakes only). Foundation multisig holds 0 OPG at genesis and bridges in from Base post-launch. The 100M x/svip pool is also funded via bridge before governance activates SVIP. The canonical 1B OPG lives as ERC-20 on Base. This avoids the depeg/run risk of seating unbacked tokens in genesis (Adam + Rahul Slack thread: "if we burn the entire 10% on Base and then put it in genesis, it might create this weird setup … small amount per genesis validator would be my recommendation").
• Add scripts/mainnet/README.md operator guide covering prerequisites, key generation, gentx flow, config edits, launch day, a citation-backed PoA enforcement note (references xrplevm/node/v10/x/poa/ante/poa.go and ante/cosmos.go:44), and a §17 "Post-launch bridge dependencies" section that documents the Foundation bridge ceremony required before any L1 transaction and before SVIP activation.
• Extract the EVM static-precompile list to scripts/lib/precompiles.sh so local_node.sh, multi_node_startup.sh, and the new mainnet script all consume the same source. This also fixes a real drift bug: multi_node_startup.sh was previously missing the TEE precompile (0x…0900).
• Fix pre-existing inconsistency: multi_node_startup.sh denom_metadata used OGETH while local_node.sh used OPG. Aligned to OPG / OpenGradient.