Add 'The Bet' section to all 4 language READMEs (en, ko, ja, zh-cn):
- Models getting cheaper every month
- Models getting smarter every month
- No single provider will dominate the future
- We leverage ALL models, not just Claude
- Architecture gets more valuable as models specialize
- We're building for the open multi-model future
Also update overview.md to move 'Better Than Pure Codex' into
Hephaestus section and add 'Better Than Pure Claude Code' section
with fundamental multi-model advantage explanation.