[BUG] Condition predicate judges recompile regex/parse pattern on every request

## Description
The three predicate judges invoked from `PredicateJudgeFactory.judge` (once per condition per rule/selector per request, on cache miss) compile/parse their pattern fresh on every call. `RegexPredicateJudge` calls `com.google.re2j.Pattern.matches(regex, input)` (no compiled-pattern cache); `PathPatternPredicateJudge` calls `PathPatternParser.defaultInstance.parse(...)` per call; `MatchPredicateJudge` runs `AntPathMatcher.doMatch` which builds an `AntPathStringMatcher` (compiling a `java.util.regex.Pattern`) per call when `cacheToPatternThreshold=0` (default). The L1 `MatchDataCache` only short-circuits rules whose conditions are all `uri`-type, so any rule mixing header/query/cookie conditions pays the full compile cost every request.

## Location
```
shenyu-plugin-base/.../condition/judge/RegexPredicateJudge.java:33
PathPatternPredicateJudge.java:39 -> PathMatchUtils.java:66
MatchPredicateJudge.java:36 -> PathMatchUtils.java:54-55
```

## Impact
`req/s x (#regex/pathPattern/match conditions in matched rules)` pattern compiles per second. A rule with 3 such conditions at 10k req/s = 30k compiles/s of CPU on the Netty event loop. Regex compilation is the dominant per-request CPU cost on the match path for non-URI-only rules.

## Suggested fix
Cache a compiled `Pattern`/`PathPattern` keyed by the condition's `paramValue` (bounded Caffeine, or precompile at rule-sync time and store the compiled pattern on `ConditionData`). For `AntPathMatcher`, enable `setCachePatterns(true)` or migrate URI matching to `PathPattern`.

## Related existing issue(s)
#6404 is about regex timeout protection, not compilation cost — distinct.

_Identified during the 2026-08-02 audit; full list in [`docs/issue-candidates-2026-08-02.md`](docs/issue-candidates-2026-08-02.md)._

Start with PredicateJudgeFactory.judge and inspect RegexPredicateJudge.java, PathPatternPredicateJudge.java, MatchPredicateJudge.java, and the referenced PathMatchUtils.java call paths. Compare the current per-call compilation behavior with the proposed cache or rule-sync approach, then verify that matching behavior is unchanged and patterns are not repeatedly compiled for each request.

Written by the indexing model from the issue text.