Automated post-upgrade gRPC transaction and query test suite

[linear]

Why

Network upgrades currently have no automated verification that the chain's full API surface still behaves correctly after the upgrade completes. An API regression found after an upgrade ships requires another network upgrade to fix. CLI issues, by contrast, can be fixed and released out-of-band — so CLI coverage is explicitly out of scope; the gRPC API is the surface that must be proven accurate.

What

As part of the upgrade flow on a testnetify-forked network, automatically run a test suite post-upgrade that exercises:

1. Every transaction type the chain supports, including all possible edge cases.
2. Every query, including all possible edge cases.

All checks run against the gRPC API. The suite passing means the upgraded chain's API surface is verified accurate.

Acceptance Criteria

• Test suite runs automatically after an upgrade completes on a testnetify network.
• Every transaction type is exercised via gRPC, including all possible edge cases.
• Every query is exercised via gRPC, including all possible edge cases.
• CLI is not part of the suite's scope.