Add scripts/check-no-test-skips.sh (run from lint) which fails the lint phase on any plain SKIP() or direct tf_skip_count manipulation; only SKIP_PLATFORM() (for genuinely platform-specific tests) is tolerated. Add FAIL() and SKIP_PLATFORM() helpers to the test framework and convert the remaining SKIP()/perf-gated skips across the suite into pass-or-fail assertions, so a suite that cannot meet its preconditions reports a red failure instead of a silent skip.