test(stack): prove registration lease lifecycle

[XnLemon]

Summary

• pin Core registration leases, Router topology status, and the Samples lease integration to exact full commit SHAs
• start Provider registration only after Catalog has published the exact Release, then inject the exact target into dedicated runtime registration profiles
• prove Nacos registration, Router watched discovery, Router-only JSON/SSE/nested calls, and Ledger provenance
• stop the Runtime B lease, require explicit Nacos removal, wait for Router to advance the same exact Release from populated to a newer empty local revision, then require the first and only acceptance Invocation to return correlated DEPENDENCY_ERROR with a matching Ledger failure
• register a replacement, wait for a still-newer Router populated revision, and prove recovery without restarting Router

Stack dependencies

• base: test(stack): prove Nacos watch refresh #5 (codex/nacos-snapshot-refresh)
• Core exact revision: feat(router): expose safe topology observation status NeKiro#107 at a737184be63533a578355f98d1b8b94648e05910 (includes the merged #106 registration lease)
• Samples: feat(runtime): use Core registration leases NeKiro-Samples#6 at 143685bebf3dc88819d3192e9047c1204a2f871d

No local replace, copied source, floating ref, direct Consumer-to-Provider path, Invocation retry, stale success, or alternate provider/Release is introduced.

Failure semantics

The previous backend job expected AGENT_UNAVAILABLE after lease removal, but current Router semantics correctly return correlated DEPENDENCY_ERROR when exact-Release topology selection has no ready endpoint. AGENT_UNAVAILABLE remains the distinct post-selection transport failure. The authenticated status assertion proves Router consumed empty before the Invocation, so the test no longer infers watch behavior from either public error and does not retry the Invocation to obtain the expected result.

Validation

• go run ./cmd/manifest-validator components.json
• go build ./...
• go test -count=1 ./internal/manifest
• go test -race ./internal/manifest
• go vet ./...
• go test -tags=e2e -run '^$' ./tests/backend
• go mod verify
• clean go mod tidy and git diff --check

The GitHub backend job is the authoritative live-container acceptance.

Fallback delta: removed 0, retained 0, added 0, net +0.
Added fallback evidence: none.

[XnLemon]

Re-reviewed current HEAD 200ec3d. I found no remaining required-closure issue. The acceptance proves the same exact Release advances populated -> newer empty -> newer populated, issues only one Invocation after empty convergence, distinguishes pre-transport DEPENDENCY_ERROR from post-selection AGENT_UNAVAILABLE, verifies the matching Ledger failure, and proves replacement recovery without Router restart. All required Stack CI, including backend and browser, is green.

中文

已复审当前 HEAD 200ec3d，未发现剩余的 required-closure 问题。验收证明同一精确 Release 按 populated -> 更新的 empty -> 更新的 populated 推进；empty 收敛后只发起一次 Invocation，区分 transport 前的 DEPENDENCY_ERROR 与选中实例后的 AGENT_UNAVAILABLE，验证对应 Ledger failure，并证明无需重启 Router 即可由替换实例恢复。Stack required CI（含 backend/browser）全部绿色。