test: cover wildcard namespace disable round-trip

[vibhor-aggr]

Summary

• add regression coverage for debug.disable() namespace strings being accepted by debug.enable()
• cover wildcard namespace patterns that start with * and include skip patterns
• verify the re-enabled namespace still matches and skips the expected debug names

Closes #918.

Verification

• npx mocha test.js --grep 'round trips wildcard namespaces through enable'
• npm run test:node
• touched-file lint: xo test.js with Node 24 compatibility shims for this repo's old lint dependencies
• git diff --check

npm run test:browser was attempted, but the local environment has no ChromeHeadless binary and Karma exits with Please, set "CHROME_BIN" env variable.