test: FGP audit coverage (#1-#12) + hardening gap-documentation (#17)

[b3y0urs3lf]

Group A: regression guards for shipped PR #13/#11 fixes. Group B: characterization tests for the #17 hardening items — pass today by documenting the gap; flip per-finding when fixed.

Refs: #6 #8 #10 #12 #17

[gemini-code-assist]

Code Review

This pull request introduces a comprehensive suite of regression, integration, and observational tests to verify fixes and document existing gaps related to resource leaks, security vulnerabilities, and consensus logic. The tests cover BoltDB handle management, libp2p stream closure, CBOR amplification risks, and T1 timer re-arming. Feedback on the PR suggests improving the diagnostic output in the IPC client tests by logging the specific attempt on which the client recovers after a server restart.

[gemini-code-assist]

For better test output and consistency with Test_IPCClient_StalePoolAfterServerRestart_SelfHeals, consider adding a log line here to indicate on which attempt the client recovered and what the initial error was. This is helpful for debugging and understanding test runs where the stale-FD error occurs intermittently.

Suggested change

	recovered = true
	require.Equal(t, "ok", out)
	recovered = true
	t.Logf("recovered on attempt %d (firstErr=%v)", attempt, firstErr)
	require.Equal(t, "ok", out)