fix(cosmos): audit and fix cosmos plugin genesis patching

[qj0r9j0vc2]

Summary

• Fix silent error swallowing in PatchGenesis by adding structured logging with slog.Logger
• Fix applyPatches misleading guard condition and add warning when plugin is nil but patch options are set
• Standardize duration format to nanoseconds (30000000000ns) matching Cosmos SDK v0.50+ convention
• Implement InflationRate patching via new patchMintParams method
• Document MinGasPrice (app.toml config) and Validators (provisioner layer) fields
• Improve extractGenesisJSON to skip JSON log lines by verifying chain_id/app_state
• Make example plugin ModifyGenesis functional
• Replace custom test helpers with stdlib strings.Contains

Test plan

• go test ./internal/plugin/cosmos/... -v passes (37 tests)
• go test ./internal/daemon/provisioner/... -v -run Genesis passes (12 tests)
• go test ./internal/infrastructure/genesis/... -v passes (7 tests)
• go build ./examples/cosmos-plugin/ builds successfully
• go test ./... full suite passes with zero failures