[yanghang8612]

What does this PR do?

Merge master (4e8389f159, including GreatVoyage-v4.8.2.4) into release_v4.8.3, following #7010. The branch includes the latest release_v4.8.3 changes through 989f3dbb4a, including the unit-test fixes in #7060, network sync hardening in #6966, and KhaosDatabase changes in #7047.

• Preserve VERSION_4_8_2_4 at fork version 39, and set VERSION_4_8_3 and ChainConstant.BLOCK_VERSION to 40. Retain the 4.8.3 fork time and 80% witness threshold.
• Resolve overlapping governance and VM configuration changes, retaining 4.8.3's strict ECDSA validation and exchange closure proposals alongside master's storage-key optimization proposal and storage migration fixes.
• Update the version assertions and VM configuration isolation test; verify that passing the 4.8.2.4 fork does not activate the 4.8.3 proposals.

Why are these changes required?

Keep release_v4.8.3 ahead of master and inherit the 4.8.2.4 fixes. Fork version 39 belongs to 4.8.2.4, so 4.8.3 needs a distinct version to preserve its independent activation gate.

This PR has been tested by:

The CI build matrix, integration smoke test, Checkstyle, and coverage gate passed on 21e6528b50 before history consolidation. The consolidated commit has the identical Git tree (f258791a3a6cbd30db486353a378fbd5a04bf1f5); this update only changes commit history.

Validated on JDK 17 / macOS ARM64 against that merge tree:

• ./gradlew clean build -x test -x :framework:generateGitProperties passed, including the framework, plugins, and p2p Checkstyle checks.
• ./gradlew test -x :framework:generateGitProperties ran 4,997 tests: 4,979 passed, 16 skipped, and 2 DNS environment failures. The framework module had 4,158 tests with no failures (12 skipped).
• All 40 tests in the three classes fixed by fix(test): stabilize unit test fixtures #7060 passed: AccountIdIndexStoreTest (4), TransactionsMsgHandlerTest (25), and RelayServiceTest (11).
• The two local failures were LookUpTxtTest.testLookUpIp_nonexistentDomain_returnsNull and StartAppArgsTest.trustIpsSkipsWhatItCannotResolve. The local resolver returned 198.18.0.225 for a .invalid hostname; the same response was confirmed using the macOS resolver. With a temporary JVM-only hosts file, the latter test passed, while the former still received a virtual address through its public-DNS fallback. These tests and the p2p code are unchanged by this PR.
• .github/scripts/check_math_usage.sh and git diff --check passed.

The Git metadata generation task was excluded because its JGit version cannot resolve this Git worktree. No build configuration, dependency, or test source was changed to work around that environment issue.

Follow up

Check the refreshed CI results on the supported build matrix.

Extra details

• Reference: feat(version): merge master to 4.8.3 #7010
• Both branch histories are preserved in a single merge commit 3ee8d8fa6e, with parents 989f3dbb4a (release_v4.8.3) and 4e8389f159 (master).