[ops/security] Automate source verification for V0 canary contracts

[FlowmemoryAI]

Context

The Base V0 canary contracts are deployed and bytecode exists at all addresses, but source verification is not automated for every contract.

Build

Add a safe verification workflow that:

• reads deployed addresses from a deployment artifact;
• uses local Basescan API key env only;
• verifies all V0 contracts;
• writes a non-secret verification report;
• documents failures and retry steps.