Release v4.0.0

[jecacs]

release!: prepare SolSharp 4.0.0 with V1 transaction reads by default

• Accept transaction V1 by default in HTTP reads and WebSocket block subscriptions
• Add minContextSlot for transaction reads and configurable signature-status queries
• Update NuGet dependencies and pin .NET SDK 10.0.401
• Fix the SourceLink vulnerability behind failing security and CodeQL restores
• Synchronize solution, benchmark, and packed Native AOT dependency locks
• Add V1 regression tests, a read-only mainnet test, and expanded AOT smoke checks
• Update release metadata, API validation baseline, documentation, and migration guide

Validated with 1,885 offline tests, a live mainnet V1 read, 28 Native AOT
checks, and 94.27% line coverage.

BREAKING CHANGE: Default transaction-version support changes from v0 to V1.
Full transaction/block options now default MaxSupportedTransactionVersion
to 1 instead of null. Use explicit version 0 for legacy/v0-only consumers.
Base58 and binary configurations require an explicit 0 or null; use
base64, JSON, or jsonParsed when accepting V1

Validation

• I added or updated deterministic tests for changed behavior.
• I ran the relevant Release build/tests and the formatting check.
• Crypto, wire-format, and program-layout changes include an upstream or independent compatibility vector.
• Untrusted-input bounds, allocation behavior, secret handling, and exception/log content were reviewed.
• Public API XML docs and relevant README/usage/changelog documentation are updated.
• Dependency changes include the affected lock files; workflow actions remain pinned to full commit SHAs.
• This change does not contain private keys, credentials, generated build output, or unrelated edits.

References

Link the issue, upstream source revision, specification, or advisory used to validate the change.