test: add BGP speaker unit and end-to-end coverage

[zhangzujian]

What this PR does

Adds focused unit and end-to-end coverage for the classic kube-ovn-speaker BGP implementation.

Unit tests

• exercise IPv4 route add/withdraw reconciliation against an in-memory GoBGP server
• verify IPv4, IPv6, and extended-nexthop path construction
• cover NEXT_HOP and MP_REACH_NLRI extraction
• cover EIP readiness/annotation filtering and deduplication through the production reconciliation path
• cover whole-second graceful-restart boundaries and reject sub-second values that would be truncated to zero by GoBGP
• cover reuse of the startup-selected cached neighbor source address

End-to-end tests

Adds a serial IPv4 Ginkgo suite using the existing Kind + containerlab + FRR topology. It verifies:

• both speaker sessions become Established
• a local-policy Pod /32 is learned from its hosting node with the exact expected nexthop and is withdrawn after Pod deletion
• switching ovn-default between cluster and local reconciles exact Pod/CIDR peer+nexthop paths without restarting speakers
• an annotated ClusterIP is advertised by both speakers and withdrawn when the annotation is removed
• FRR paths are read from the full IPv4 unicast RIB because FRR 9.1.3 omits peerId from prefix-specific JSON output

Withdrawal checks require the route path to be absent while both BGP sessions remain Established, so session loss or an invalid/stale retained path cannot produce a false pass.

The suite is wired into e2e-build, a dedicated Make target, and the x86 workflow. Failure artifacts include FRR summary/RIB output, speaker DaemonSet/Pod state and logs, events, audit logs, and kubectl ko log; setup failures upload an explicit unavailable marker when the cluster never becomes usable.

Local verification

All local compile, test, and static-check commands ran with MemoryMax=512M:

• go test ./pkg/speaker -count=1 -cover (39.9%)
• go test -race ./pkg/speaker -count=1
• go vet ./pkg/speaker
• go test test/e2e/bgp/frr.go test/e2e/bgp/frr_test.go -count=1
• workflow YAML parse and BGP job wiring assertions
• git diff --check

The privileged Kind/containerlab E2E and repository golangci-lint are delegated to GitHub Actions.

[coveralls]

Coverage Report for CI Build 31926766507

Coverage increased (+0.3%) to 32.744%

Details

• Coverage increased (+0.3%) from the base build.
• Patch coverage: 11 of 11 lines across 1 file are fully covered (100%).
• 4 coverage regressions across 2 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

4 previously-covered lines in 2 files lost coverage.

File	Lines Losing Coverage	Coverage
pkg/bfddsupervisor/socket.go	2	51.58%
pkg/ovs/ovn-nb-bfd.go	2	61.61%

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Coverage Stats

Relevant Lines:	64588
Covered Lines:	21149
Line Coverage:	32.74%
Coverage Strength:	0.38 hits per line

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💛 - Coveralls