[BigDataDZ]

When another server process renames a datasource code, the current process creates a pool under the new code but leaves the previous pool cached and open. Repeated renames accumulate connections until shutdown.

On a pool-cache miss, retire previous keys whose recorded datasource ID matches the current source before creating its replacement. Preserve unrelated datasource pools and the constant-time cache-hit path. Use the existing pool close/error-handling contract and weak connection snapshots; no baseline changes.

Validation: sync and async repeated-rename regressions fail before the change;59 lifecycle/disabled-source/dialect tests pass after it. Tests retain a second datasource pool and verify that old keys are removed, old pools close, and cache size stays bounded. Independent review/probes found no actionable issues. Based directly on main87c2966, which already includes #78.

中文：修复跨进程修改数据源代号后旧连接池遗留的问题，避免反复改名积累连接。

Full combined verification of#80–#82 on main87c2966:811 passed,5 failed,15 skipped; unchanged main794 passed,5 failed,15 skipped. The failing test names match exactly;17 new regression tests pass, with no new skips. Diagnostic runs use node --test --test-force-exit because existing failed tests retain resources. Architecture guard36 errors/2 warnings (baseline shape37 errors); fixture eval14/14 with2 L3 judge results pending. Baseline file unchanged. Combined branch codex/oct27-functional-fixes-integration at319fbbb; no upstream merge performed. CI is not claimed fully green.