- IssueAdmin now rejects past/now ExpiresAt with CodeMcpTokenExpiresRequired
- TestIssueAdmin_ExpiresMustBeFuture covers the new path
- IssueSystemToken doc comment notes pgRepo currently ignores ctx tx; Part 3
must add Repository.WithTx for true same-transaction guarantee with
acp_sessions (spec §6.1)
- New scope_test.go (whitebox) verifies JSON round-trip preserves nil-vs-empty
semantics on Tools / ProjectIDs and exercises AllowsTool / AllowsProject
edges that Authenticate / future tool gating depend on