Strengthen localized README drift checks

[baskduf]

Description

The localized READMEs are useful, but drift can happen when install commands, core warnings, or command references change in only one language. Existing tests cover core workflow presence; strengthen them to catch release/version and important warning drift.

Acceptance Criteria

• Ensure all README*.md files reference the same stable release tag in install examples.
• Ensure all localized READMEs preserve the core limitation warning concepts:
  • FableCodex does not clone, unlock, or replace Fable 5.
  • It does not change model weights, context length, training, or hidden safety systems.
• Ensure command reference sections include the same core commands across languages.
• Test failures should identify the exact README and missing/mismatched concept.

Notes

The test does not need perfect translation equivalence; concept and command parity is enough.