chore: Update examples

[fabianhug]

to require at least 2 DVNs for production OApps; added warnings and documentation links in config files and README.md files across multiple examples.

[cursor]

PR Summary

Medium Risk
Mostly documentation/config template changes, but several example layerzero.config.ts pathways now include a <SECONDARY_DVN> placeholder in requiredDVNs, which can break copy-paste wiring until replaced with a real provider.

Overview
Adds prominent production safety warnings across many example README.md files stating that OApps (including read OApps) must use at least two DVNs, with links to DVN provider addresses and the single-DVN migration guide.

Updates multiple example config files to reinforce this requirement: some add TODO comments near requiredDVNs, while others change pathway definitions from a single ['LayerZero Labs'] DVN to ['LayerZero Labs', '<SECONDARY_DVN>'] (and annotate that production confirmations are typically 15+).

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[github-actions]

🧪 E2E Test Status

E2E tests are non-blocking and validate real blockchain interactions. Failures may occur due to network issues, RPC rate limits, or external service downtime.

Test Runs (Newest First):

• ✅ Run #6755 - Passed - 2026-05-06 19:47 (UTC)

[fabianhug]

@St0rmBr3w please check the above & approve so we can close this