docs: purge every literal "--max-iterations 0" mention from docs and tests

[JonyanDunh]

Follow-up to #16. The previous PR removed the canonical `--max-iterations 0` example but left explanatory sentences like "you no longer need to pass `--max-iterations 0`" in the docs and a backward-compat test name in `test/setup.test.js`. Those still printed the literal `--max-iterations 0` to readers, defeating the point of the cleanup. This PR removes every remaining occurrence.

Why

Telling users "you don't need to write `--max-iterations 0` anymore" still shows them `--max-iterations 0`. A new user reading the docs has no prior knowledge of the legacy form, so explaining what NOT to write just plants the wrong syntax in their head. Cleaner: omit the deprecation note entirely. New users see only the "omit the flag for unlimited" guidance. Existing users who happen to pass `0` keep working silently.

What changed

commands/help.md

• --max-iterations Options description: dropped the trailing "You no longer need to pass `--max-iterations 0`..." sentence
• Best Practices fix(commands): /watchdog:stop was pointing at a non-existent script #4: dropped the trailing "you do not need to pass `--max-iterations 0`" sentence

scripts/setup-watchdog.js printHelp()

• Dropped the "You do NOT need to pass `--max-iterations 0` anymore." line from the help-output trailer

All 7 READMEs (README.{md,zh,es,ja,ko,vi,pt}.md)

• --no-classifier subsection paragraph: dropped the "you no longer need to pass `--max-iterations 0`" trailing sentence
• Best Practices fix(commands): /watchdog:stop was pointing at a non-existent script #4 paragraph: dropped the same trailing sentence

test/setup.test.js

• Renamed the legacy backward-compat test:
  • Before: `setup --no-classifier + --max-iterations 0 is allowed (infinite loop, manual stop only)`
  • After: `setup --no-classifier with no max cap is allowed (infinite loop, manual stop only)`
• Test args changed from `['build', '--no-classifier', '--max-iterations', '0']` to `['build', '--no-classifier']`
• Added a comment explaining that the recommended way to express "unlimited" is omission, and that the state file's `max_iterations=0` default is what makes the stop hook treat the loop as uncapped

Backward compatibility

Identical to the previous state. The parser still accepts `--max-iterations 0`; the stop hook still treats `max_iterations=0` as "no cap" (the `> 0` guard fails). Anyone who was passing `0` explicitly keeps working. The only change is that the literal string `--max-iterations 0` no longer appears anywhere in the docs, the in-Claude-Code help, or test names that get printed in CI logs.

Confirmed via `Grep "--max-iterations 0"` returning zero matches across the entire repo.

Test plan

• 132-test suite still passes (132 active + 2 skipped, 0 failures)
• `node --test test/*.test.js` clean
• `Grep "--max-iterations 0"` returns zero matches across the repo
• CI will confirm on the standard matrix

Scope

• `commands/help.md` — 2 sentence drops
• `scripts/setup-watchdog.js` — 1 line drop in `printHelp()`
• `README.md` + 6 translations — 2 sentence drops each (14 total)
• `test/setup.test.js` — 1 test renamed + args trimmed

Zero changes to `lib/`, `hooks/`, `.claude-plugin/`, or any other production code. No version bump.

Co-Authored-By: Claude Opus 4.6 (1M context) noreply@anthropic.com