perf(detector): hoist inline Pattern.compile to static finals (RAN-32)

[aksOps]

Summary

Removes regex recompilation from hot paths in three Java detectors. Each
inline Pattern.compile(...) call inside detect() is replaced with a
reference to a private static final Pattern constant compiled once at
class load.

• ConfigDefDetector: VALUE_KEY_RE, QUOTED_STRING_RE (was lines 160 & 168)
• KafkaDetector: QUOTED_TOPIC_RE (was line 87)
• SpringRestDetector: BARE_QUOTED_RE (was line 345)

These detectors run across every Java source file during indexing, so the
inline compiles were a measurable allocation/CPU hit at Code IQ scale.

Pure refactor — same regex source, same flags, no behavioral change.

Reference style follows the existing static-final pattern already used
throughout LdapAuthDetector and the rest of the file in each detector.

Refs: RAN-32, parent RAN-1, source audit RAN-6.

Test plan

• mvn -Dtest='ConfigDefDetectorTest,SpringRestDetectorExtendedTest,JavaDetectorsBranchCoverageTest,JavaDetectorsCoverageTest,JavaDetectorsExtendedTest,JavaDetectorsTest' test
  → 344 tests, 0 failures, 0 errors
• grep -n "Pattern.compile" <files> confirms no inline compiles remain in detect paths

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
87.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[aksOps]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

🤖 Generated with Claude Code

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