The CI platform coverage gate (macOS/Windows) only executes tests
matching ^(TestAllShortcuts|TestCrossPlatformCoverage). The edu/college
test functions used standard names and were not exercised during the
platform coverage run, causing 73.89% changed-code coverage (target 100%).
Changes:
- Rename all edu/college test functions with TestCrossPlatformCoverage prefix
- Add edu products to command_matrix_test.go selected map
- Add TestCrossPlatformCoverageOpenSupplementServersIncludesEduEndpoints
in pkg/edition to cover the new supplement server entries
Local verification: coverage-gate-platform reports 100.0000% (3336 stmts).