Reject invalid RTM coinbase dev rewards

[MoneroOcean]

Motivation

• Fix a fail-open validation path where malformed rpcData.coinbasedevreward could be skipped as an output but its value would still inflate the pool payout and change the coinbase transaction version.
• Ensure daemon-supplied dev-reward data is treated as trusted-only after explicit validation so miners are not given invalid block templates that waste work.

Description

• Add hasValidCoinbaseDevReward(rpcData) which uses validateCoinbaseDevReward() and throws on malformed dev-reward objects instead of silently returning false.
• Change generateTransactionOutputs() to accept a hasDevReward flag and only add coinbasedevreward.value into reward accounting when the dev reward has been validated.
• Use the validated hasDevReward state for coinbase transaction version selection so the version matches the actual emitted outputs.
• Add a regression test in tests/test.js asserting that a malformed coinbasedevreward.scriptpubkey causes RtmBlockTemplate() to throw (Invalid coinbase dev reward).

Testing

• Ran a targeted RTM validation smoke test with dependency stubs (simulating absent, valid, and malformed coinbasedevreward) and the stubbed tests passed (valid/absent succeed, malformed throws as expected).
• Ran git diff --check to ensure no whitespace/patch issues and it passed.
• Attempted npm test but it was blocked by the environment/registry returning 403 Forbidden while fetching dependencies so full test suite could not be executed.
• Attempted node --test --test-reporter=spec tests/test.js but it failed in this environment due to the missing native addon build artifact (../build/Release/blocktemplate), so the full test run could not complete.

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Codex Task