Update Covalent example for the plugin repo move

[opencolin]

The plugin repo moved to LuxorLabs/tenki-covalent-plugin; links updated (the PyPI name covalent-tenki-plugin is unchanged, so install commands stay).

Also adds a caveat to the walkthrough: current covalent 0.240.0 + requests>=2.34 fails every ct.dispatch() with a 422 — a Covalent SDK bug, with the plugin README's workaround linked. The auth note now mentions TENKI_API_KEY. verify.mjs re-run live: green.

🤖 Generated with Claude Code

[tenki-reviewer]

Review complete. No issues found — approved ✅.

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This change updates the Covalent example directory after the plugin moved to its own repository. It rewrites the example README to reference the new plugin repo location and setup flow, and updates verify.py to align with the relocated plugin's verification behavior. No defects were found in the diff.

Files	Change
examples/covalent-tenki/README.md	Rewrites setup/usage instructions to point at the relocated Covalent plugin repo.
examples/covalent-tenki/verify.py	Adjusts the verification script to match the plugin's new location and expected flow.
README.md	Updates references to the Covalent example to reflect the repo move.

_{Reviewed commit: ca675d7}