Fix public recall eval case refresh

[sheawinkler]

Summary

• make recall eval case GET/refresh routes Go-native in the public gateway
• refresh saved cases from live topic rollups and file-backed memory instead of stale defaults
• update route ownership tests and add a live-memory refresh regression test

Verification

• GOCACHE=/Volumes/wd_black/codex_go_cache GOMODCACHE=/Volumes/wd_black/codex_gomod_cache go test . -run 'TestProxyForwardsBatchAndOpsQueuePaths|TestRecallEvalCasesRefreshUsesLiveFileBackedMemory|TestMemoryRecallEvaluateSaved(IsGoNative|ScoresGraphContribution)' -count=1
• GOCACHE=/Volumes/wd_black/codex_go_cache GOMODCACHE=/Volumes/wd_black/codex_gomod_cache go test . -count=1