- detect-changes: VERSION/Makefile changes trigger full test matrix
- test-sdk: fix service_destroy treating "not found" as success
- test-sdk: skip qr_generate on missing deps instead of failing
- test-sdk: increase backoff cap from 10s to 30s for overloaded pools
- test-sdk: increase no-match retry from 3 to 5 with longer delay
- test-sdk: detect nginx error messages (bad gateway, etc) as 5xx
- test-sdk: show HTTP status and error details on test failure