#46 Consolidate redundant ClassGraph scans during Element loading

[krh372]

Summary

• DefaultElementLoaderFactory ran ~11 independent ClassGraph scans per Element load: 5 package-scoped scans (services, produced events, consumed events, default attributes, required attributes), each also triggering its own unrestricted probe scan via rejectOtherElementPackages, plus the initial module-definition scan.
• Consolidated down to 3 scans: the module-definition scan (unavoidably unrestricted, since the element's package isn't known yet), a single reject-list probe (findOtherElementPackageNames, computed once instead of once per extraction), and one shared enableAllInfo() scan (scanElementPackage) that all five metadata extractions now read from instead of each re-scanning.
• No behavior change — enableAllInfo() is a strict superset of every info-flag combination the 5 original scans requested individually.

Fixes #46

Test plan

• mvn -pl sdk-spi -am install — compiles cleanly
• mvn -pl sdk-test test — 27/27 tests pass, including ElementLoaderTest, ApiElementLoaderTest, FlatElementPathLoaderTest, which exercise the full isolated-classloader element-loading pipeline (services, produced/consumed events, default/required attributes) against real test-element fixtures
• mvn -pl sdk-spi-guice test — 3/3 tests pass
• Manual smoke test against a running jetty-ws instance