The lint step in Dockerfile.lint now passes --panicOnWarning alongside
--printPathWarnings. Until now Hugo printed "Duplicate target paths"
when two pages wrote the same output file and still exited 0, so the
lint passed while one page was silently lost. The flag turns that
warning, and every other Hugo warning, into a failed lint.
script/test and the deploy build are unchanged. The comments in
Dockerfile.lint, script/lint and script/check, the README entry for
script/lint, and TODO.md now describe the stricter lint.
Model: opus-5-5
sneak