[bihaoxwork]

Changing <APP>.use.secure at runtime can leave existing clients connected to the old port because EVCacheClientPool does not subscribe to this setting. Subscribe to the application property, with the existing evcache.use.secure fallback and false default, and clear and force-refresh the pool when its effective value changes. This uses the same rebuild behavior as timeout and pool-size changes.

The change covers application-level and global secure-mode changes. Discovery continues to apply server-group overrides; changes made only to those overrides do not gain a new subscription in this PR.

Validation:

• Added five regression tests covering disabling and enabling secure mode, cleanup of all replica clients, global fallback updates, removal of an application override, and precedence over global changes. The four refresh-triggering cases fail before the fix and all five pass after it.
• Ran the complete core test suite with Java 17: ./gradlew :evcache-core:test --no-daemon --console=plain.