fix(redis): persist no-expiration TTL updates

[HandSonic]

Summary

• Send Redis PERSIST when an existing key changes from a positive TTL to no expiration.
• Add regression coverage for TTL command selection.

Tests

• RedisScriptExecutorUpdateTest: 7/7
• Redis plugin test suite: 58/58
• Redis plugin package build

Fixes #2681

[openai0229]

The TTL transition logic is correct: a positive TTL still emits , and changing an existing non-permanent key to emits without affecting type-replacement flows. Tests cover the command selection. Approved.

Superseded by a corrected review because shell quoting corrupted the submitted text.

[openai0229]

The TTL transition logic is correct: a positive TTL still emits EXPIRE, and changing an existing non-permanent key to -1 emits PERSIST without affecting type-replacement flows. Tests cover the command selection. Approved.

[openai0229]

已基于最新主线复核并完成 Redis 7 实测。TTL 更新现在由用户提交的新值决定：正数执行 EXPIRE，-1 执行 PERSIST；不再依赖可能过期的旧 TTL 快照。聚焦测试 8/8、Redis 插件测试 60/60、Community 后端 48 模块打包及 Playwright 正数、转 -1、陈旧快照、取消路径均通过。