fix(vaultsfyi): bind execute_step network to the wallet chain

[SashaMIT]

Summary

• execute_step accepted an agent-chosen network and fetched/executed vaults.fyi actions without checking the connected wallet chain. Sibling claim_rewards already rejects cross-network claims.
• This PR mirrors that guard: require a supported wallet chainId, and reject when args.network does not match it (before any API call or sendTransaction).

Sibling of #1409 (CDP Permit2 / swap-submit retry). Same dogfood pass, different provider and root. Does not reopen that PR's findings.

Test plan

• pnpm exec jest --testPathPattern='vaultsfyi/vaultsfyiActionProvider' --coverage=false (28/28)
• Regression: mismatched args.network vs wallet chain returns the claim_rewards-style error and does not call fetch/sendTransaction
• Regression: missing wallet chainId returns Invalid network

Made with Cursor

[cb-heimdall]

🟡 Heimdall Review Status

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Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2

[SashaMIT]

Consolidating our open queue to reduce triage load. Closing this for now; the core set we are keeping open is #1392, #1404, #1405, #1409, #1421, #1423. Happy to reopen or refile this specific fix if a maintainer wants it.