fix(plugin): preserve dynamic candidate matching after cache warmup - #8106

Fixes #7981.

A path cache can retain a generic selector or rule and bypass a competing condition that would win for a later request on the same path. Require the entire enabled candidate set to be path-determined before storing a positive result.

• Allow positive caching only for known URI-only operators without RESTful extraction. TimeBefore/TimeAfter and unknown SPI operators bypass positive caching; disabled candidates do not block it. URI-only candidate sets retain caching.
• Build the default cache key from RequestUrlUtils.getRewrittenRawPath, matching URIParameterData. Otherwise requests with the same original path but different rewritten paths can reuse the wrong selector/rule. Existing WebSocket and MCP overrides already use this helper.
• Keep negative candidate-set eligibility and cross-selector rule-cache isolation separate ([BUG] Path-only negative match cache suppresses later requests that satisfy dynamic conditions #7977 and [BUG] Rule match cache reuses a rule from another selector for the same request path #7976).

Validation on Microsoft OpenJDK 17.0.18 through mvnw.cmd:

• All 14 execution-path regressions/controls pass: six header/query/method selector/rule cases, two URI-only/disabled-candidate controls, four deterministic time-boundary cases and two rewritten-path cases. Removing the respective fixes reproduces the six dynamic, four timed and two rewritten-path failures; the URI-only controls pass.
• The complete 11-module affected reactor passes unit tests and Checkstyle, including all 320 shenyu-plugin-base tests, with zero failures/errors/skips in that module.
• Apache RAT passes across the affected reactor; git diff --check passes.

Tests use real BaseDataCache, MatchDataCache and matching, Spring mock exchanges, and a controlled clock for time predicates. No deployed gateway or Docker E2E run is claimed. The existing Byte Buddy agent was supplied for local Mockito attachment.

• Regression tests included.
• Full repository clean install (affected reactor validation is recorded above).