JSpecify migration — Phase 4: consensus and medium modules

[jflo]

Parent: #10440

Scope

Medium-sized modules (~40-80 production files). Should be tackled after Phase 1, since several of these depend on ethereum/core and ethereum/eth already being annotated.

One PR per module:

• consensus/ibft (52 files)
• consensus/qbft (40 files)
• consensus/qbft-core (60 files)
• ethereum/trie (42 files)
• metrics/core (45 files)

Recipe

Apply the per-module template from the parent issue. See #10370 for a worked example.

Notes

• The QBFT pair (qbft and qbft-core) shares a lot of types — annotate them together or in tight succession to avoid round-tripping null contracts.
• ethereum/trie interacts heavily with tuweni-bytes and Guava — expect to apply requireNonNull(...) at those boundaries since neither is JSpecify-annotated.

Definition of done

• Each module's build.gradle carries the NullAway block.
• ./gradlew :<module>:compileJava passes.
• CI green on a full build.

[abhay-dev2901]

@jflo
I’m working on the metrics/core module from this phase. I’ll open a PR for enabling NullAway/JSpecify there and fixing the resulting null-safety
violations.