[Task] Update stale matching-cache documentation after Trie removal #7979

Problem

The matching-path documentation in AbstractShenyuPlugin.execute still describes an L1 LRU cache followed by an L2 Trie cache and then the default matching strategy. The Trie implementation was removed in commit 295a12bb56539465ba3d979c0e8bbf13b2696fce (PR #6303).

On current master, the rule path checks MatchDataCache and then calls defaultMatchRule on a cache miss. There is no Trie lookup between these steps. The stale comments mislead readers investigating matching behavior or performance.

Requested documentation update

• Replace the obsolete L1/L2/Trie comments with the actual flow: bounded match-result cache, then default candidate matching on a miss.
• Check maintained matching documentation for the same outdated description and update any remaining references that describe Trie as a current runtime component.
• Keep intentional historical references intact.

This is a documentation/comment correction. It does not request restoring Trie, changing matching precedence, or modifying runtime behavior.

References

• Reviewed master: 862f5e37e894bd8cef85ef540a8629f313e9ecdf
• Stale comments
• Trie removal

Acceptance criteria

Current matching-path documentation agrees with the implementation and no longer claims a live L2 Trie lookup. No functional changes are needed.

Searched existing issues for trie comment; no matching documentation task was found.